United States v. Leeper

majority opinion

22-3110-cr

United States Court of Appeals

for the Second Circuit

August Term 2024

Argued: February 5, 2025

Decided: August 13, 2026

No. 22-3110

UNITED STATES OF AMERICA,

Appellee,

— v. —

KYLE M. LEEPER,

Defendant-Appellant. *

Appeal from the United States District Court

for the Northern District of New York

No. 5:19-cr-0301, David N. Hurd, Judge

Before: PARKER, SULLIVAN, and BIANCO, Circuit Judges.

Defendant-Appellant Kyle Leeper appeals from a judgment entered by the United States District Court for the Northern District of New York (David N. Hurd, Judge) on November 29, 2022. Leeper was convicted on his plea of guilty to one

The Clerk of Court is respectfully directed to amend the caption as set forth above. count of intentional murder while engaged in a controlled substance oﬀense, in violation of 21 U.S.C. § 848(e)(1)(A); one count of conspiring to distribute and possess with intent to distribute methamphetamine, in violation of 21 U.S.C. §§ 841(a)(1) & (b)(1)(A), 846; and one count of knowingly possessing a ﬁrearm and ammunition after having been convicted of a felony, in violation of 18 U.S.C. §§ 922(g)(1), 924(a)(2). As part of his plea agreement, Leeper reserved the right to challenge the district court’s denial of his pretrial motions, including his motions to suppress evidence seized from his vehicle and evidence obtained by taking a buccal swab of his DNA.

On appeal, Leeper challenges the denial of those motions, arguing that: (1) the search warrant aﬃdavit did not establish probable cause to search his DNA because it did not identify any viable DNA samples with which his DNA could be compared; (2) the search warrant was invalid because it was issued ex parte even though there was no reason to proceed ex parte; and (3) the oﬃcers’ decision to hold his vehicle was unreasonable under the Fourth Amendment, rendering the resulting search unreasonable as well.

For the reasons set forth below, we conclude that: (1) the search warrant application established probable cause to search Leeper’s DNA; (2) Leeper was not entitled to notice and an opportunity to be heard prior to the issuance of the search warrant, and thus the warrant was properly issued ex parte; and (3) the oﬃcers’ decision to hold Leeper’s vehicle was reasonable under the Fourth Amendment. Accordingly, we AFFIRM the judgment of the district court.

Judge Sullivan concurs in the judgment in a separate opinion.

BENJAMIN SILVERMAN, Law Offices of Benjamin Silverman,

New York, New York, for Defendant-Appellant.

STEVEN D. CLYMER, (Thomas R. Sutcliffe, on the brief),

Assistant United States Attorneys, for John A. Sarcone III,

United States Attorney for the Northern District of New

York, for Appellee.

J OSEPH F. B IANCO , Circuit Judge:

Defendant-Appellant Kyle Leeper appeals from a judgment of the United

States District Court for the Northern District of New York (David N. Hurd, Judge)

entered on November 29, 2022. Leeper was convicted on his plea of guilty to one

count of intentional murder while engaged in a controlled substance oﬀense, in

violation of 21 U.S.C. § 848(e)(1)(A); one count of conspiring to distribute and

possess with intent to distribute methamphetamine, in violation of 21 U.S.C.

§§ 841(a)(1) & (b)(1)(A), 846; and one count of knowingly possessing a ﬁrearm and

ammunition after having been convicted of a felony, in violation of 18 U.S.C.

§§ 922(g)(1), 924(a)(2). As part of his plea agreement, Leeper reserved the right to

challenge the district court’s denial of his pretrial motions, including his motions

to suppress evidence seized from his vehicle and evidence obtained by taking a

buccal swab of his DNA.

On appeal, Leeper challenges the denial of those motions, arguing that:

(1) the search warrant aﬃdavit did not establish probable cause to search his DNA

because it did not identify any viable DNA samples with which his DNA could be

compared; (2) the search warrant was invalid because it was issued ex parte even

though there was no reason to proceed ex parte; and (3) the oﬃcers’ decision to

hold his vehicle was unreasonable under the Fourth Amendment, rendering the

resulting search unreasonable as well.

For the reasons set forth below, we conclude that: (1) the search warrant

application established probable cause to search Leeper’s DNA; (2) Leeper was not

entitled to notice and an opportunity to be heard prior to the issuance of the search

warrant, and thus the warrant was properly issued ex parte; and (3) the oﬃcers’

decision to hold Leeper’s vehicle was reasonable under the Fourth Amendment.

Accordingly, we AFFIRM the judgment of the district court.

BACKGROUND 1

Leeper was engaged in buying and selling methamphetamine in Indiana,

California, and New York. In early 2019, he traveled to California along with a

housemate, Ramon Nieves Cotto, to purchase methamphetamine. He was

contacted by a woman named Arlene Rodriguez, who oﬀered to help him

purchase drugs. Rodriguez introduced Leeper to Robert Chavez, who arranged

for Leeper to buy three pounds of methamphetamine for $5,000 from his supplier.

Chavez met the supplier and exchanged Leeper’s $5,000 for a backpack, which he

gave to Leeper.

The following facts, which are undisputed, are drawn from the Memorandum-Decision and Order entered by Judge Hurd on December 22, 2021, as well as the Plea Agreement that Leeper and the government entered into on May 11, 2022.

Later that day, Leeper discovered that there was substantially less than three

pounds of methamphetamine in the backpack. In response, Leeper took

Rodriguez hostage at gunpoint and forced her to take him back to Chavez. He

then abducted Chavez, and the group drove around Los Angeles trying to get

more money or drugs to recoup Leeper’s loss. That night, Leeper ordered

Rodriguez to drive to Walmart, where he instructed Cotto to purchase zip ties.

Leeper then bound Chavez’s hands and feet with the zip ties. With a bound

Chavez in tow, Leeper then directed Rodriguez to drive to a deserted area near

Barstow, California, where he removed Chavez from the car, led him away, and

shot him in the back eight times, killing him. Cotto and Rodriguez remained in

the car. Leeper returned to the car alone, and he, Cotto, and Rodriguez drove to

Cortland, New York. Over the course of the trip, Leeper and Rodriguez developed

a romantic relationship, and she continued to assist him with buying and selling

methamphetamine.

On February 19, Leeper and Rodriguez were stopped by oﬃcers from the

Cortland County New York Sheriﬀ's Oﬃce (“CCSO”) while Leeper was driving a

pickup truck. The oﬃcers detained Leeper; held the pickup truck after learning

that neither Leeper nor Rodriguez possessed a valid license and that the vehicle

did not have a valid registration; and conducted an inventory search of the truck,

where they found a ﬁrearm, ammunition, and four pounds of methamphetamine.

The oﬃcers then arrested Leeper and Rodriguez.

Following her arrest, Rodriguez told CCSO oﬃcers that Leeper smoked

methamphetamine, that she believed he was selling methamphetamine, and that

she had seen him with both a hand gun and a stun gun. In addition, Rodriguez’s

attorney told CCSO oﬃcers that Rodriguez was present during Chavez’s murder

and was willing to speak with the oﬃcers about it. A few weeks later, CCSO

oﬃcers were contacted by a detective in California who was investigating

Chavez’s homicide.

On April 8, a Cortland County judge issued a warrant to search Leeper’s

person for evidence of second-degree murder, including by collecting his DNA

from a buccal swab. The warrant was issued based on a probable cause aﬃdavit

submitted by Sergeant Garry Williams of the CCSO. Leeper was in custody at the

time. The search warrant identiﬁed various pieces of physical evidence found at

the scene of the homicide, including eight .380 caliber ﬁred cartridge casings, seven

.380 caliber projectiles, and cut zip ties.

In 2021, Leeper moved to suppress both the evidence found in his vehicle

and evidence derived from the DNA sample. Following an evidentiary hearing,

the district court denied both motions. See generally United States v. Leeper, 577 F.

Supp. 3d 48 (N.D.N.Y. 2021). With respect to the vehicle search, the district court

found that, under the totality of the circumstances, the oﬃcers’ decision to tow

Leeper’s truck was reasonable because neither passenger was licensed to drive it,

the truck had no valid registration, and the truck had a severely cracked

windshield, making it unﬁt for driving. Id. at 63–64. The district court rejected

Leeper’s argument that the decision did not comport with department policy and

was therefore unreasonable, noting that non-compliance with a department policy

is not dispositive of the legality of a search and that “there is uncontradicted

evidence that Wright complied with standard practice even if he had not strictly

followed the written policy.” 2 Id. at 63.

With respect to the DNA sample, the district court found that there was

probable cause for the warrant to issue, given that there was substantial evidence

linking Leeper to Chavez’s murder and “any number of physical instrumentalities

Below, Leeper also challenged his temporary detention and the decision to conduct an inventory search of his vehicle after it was taken into custody. He does not pursue these arguments on appeal. See Chevron Corp. v. Donziger, 990 F.3d 191, 203 (2d Cir. 2021) (“Arguments not raised on appeal are deemed abandoned and need not be reviewed by this Court.”).

explicitly tied to Chavez’s murder.” 3 Id. at 72. The district court also rejected

Leeper’s procedural due process challenge to the ex parte warrant proceeding,

stating that “Leeper has failed to point to any support for the notion that the

federal concept of due process would also require an opportunity to be heard

before a search warrant could issue to seize DNA.” Id. Accordingly, the district

court denied Leeper’s suppression motion in its entirety.

Ultimately, Leeper pleaded guilty to three counts: (1) intentional murder

while engaged in a controlled substance oﬀense; (2) conspiring to distribute

methamphetamine; and (3) possessing a ﬁrearm knowing that he had previously

been convicted of a felony. However, his plea agreement permitted him to appeal

the district court’s decision to deny his suppression motion as to: “(a) whether

evidence located in and seized from the pickup truck occupied by Kyle M. Leeper

and Arlene N. Rodriguez on February 19, 2019, should have been suppressed

under the Fourth Amendment; and (b) whether a search warrant permitting the

taking of a buccal swab from Kyle M. Leeper on or about April 10, 2019, was

constitutionally invalid because it was issued without a showing of probable cause

and ex parte.” App’x at 221. The plea agreement provided that if Leeper prevails

Below, Leeper also argued that the warrant application was supported by insufficiently reliable evidence. Again, that argument is not raised on appeal.

on appeal, “he will be permitted to withdraw his guilty plea without penalty.” Id.

The district court ultimately sentenced Leeper to forty years in prison on both the

murder charge and drug charge and ten years on the ﬁrearm charge, all to run

concurrently. This appeal followed.

DISCUSSION

The Fourth Amendment provides that “[t]he right of the people to be secure

in their persons, houses, papers, and eﬀects, against unreasonable searches and

seizures, shall not be violated.” U.S. C ONST . amend. IV. On appeal, Leeper asserts

that the searches of both his DNA and his vehicle violated the Fourth Amendment

and challenges the district court’s denial of his motions to suppress that evidence.

“On an appeal challenging a district court’s ruling on a motion to suppress

evidence, we review its legal conclusions de novo and its ﬁndings of fact for clear

error.” United States v. Iverson, 897 F.3d 450, 459 (2d Cir. 2018). “In reviewing the

denial of such a motion, we view the evidence in the light most favorable to the

government.” United States v. Delva, 858 F.3d 135, 148 (2d Cir. 2017) (alteration

adopted) (internal quotation marks and citation omitted). “[W]e may aﬃrm the

denial of the suppression motion on any basis for which there is a record suﬃcient

to permit conclusions of law, including grounds upon which the district court did

not rely.” United States v. Estrada, 430 F.3d 606, 609–10 (2d Cir. 2005).

I. DNA Search

As part of their investigation, CCSO oﬃcers obtained a warrant to search

Leeper’s person for evidence of second-degree murder, including by taking a

buccal swab of his DNA. Leeper challenges the validity of the DNA search on two

grounds. The ﬁrst is substantive: Leeper argues that the warrant application failed

to establish probable cause that his DNA was likely to contain evidence of a crime

because it did not identify any relevant DNA samples with which Leeper’s DNA

could be compared. The second is procedural: Leeper argues that he was denied

procedural due process because the oﬃcers obtained a warrant to take a sample of

his DNA without providing him notice or an opportunity to be heard. We address

each of these issues in turn.

a. Probable Cause

In evaluating probable cause, a judge must “make a practical,

common-sense decision whether, given all the circumstances set forth in the

aﬃdavit before him, . . . there is a fair probability that contraband or evidence of a

crime will be found in a particular place.” Illinois v. Gates, 462 U.S. 213, 238 (1983).

“Due to this subjective standard, a reviewing court generally accords substantial

deference to the ﬁnding of an issuing judicial oﬃcer that probable cause exists,

limiting our inquiry to whether the oﬃcer had a substantial basis for his

determination.” United States v. Raymonda, 780 F.3d 105, 113 (2d Cir. 2015) (internal

quotation marks and citation omitted); see also Gates, 462 U.S. at 236 (“A

magistrate’s determination of probable cause should be paid great deference by

reviewing courts.”) (internal quotation marks and citation omitted). “Reasonable

minds frequently may diﬀer on the question whether a particular aﬃdavit

establishes probable cause.” United States v. Leon, 468 U.S. 897, 914 (1984).

Accordingly, the Supreme Court has “repeatedly said that after-the-fact scrutiny

by courts of the suﬃciency of an aﬃdavit should not take the form of de novo

review.” Gates, 462 U.S. at 236.

Leeper argues that there was no probable cause to search his DNA because

the oﬃcers did not establish that there were any DNA samples with which to

compare his DNA. His DNA alone, he argues, is useless; unless the oﬃcers

established that there were usable DNA samples collected at the scene or in other

relevant locations with which Leeper’s DNA could be compared, there was no fair

probability that evidence of a crime would be found in his DNA on its own. 4

While the parties point us to conﬂicting lower court authority, 5 this

4 As a threshold matter, the government’s argument that Leeper failed to challenge the search warrant on these grounds below and therefore review in this court should be for plain error is without merit. While Leeper’s pretrial motion below made the factually inaccurate argument that “there are no evidentiary items connected to the murder that are identified,” it also argued that “flowing from that is the fact that no evidentiary items have been swabbed for DNA such that a comparison would be possible.” Gov’t App’x at 30. Accordingly, we consider whether, on de novo review, the district court erred in concluding that the search warrant for Leeper’s DNA was supported by probable cause. 5 Compare, e.g., United States v. Marshall, No. 11-CR-00381, 2012 WL 2994020, at *3 (W.D.N.Y. July 20, 2012) (“Without evidence that the DNA samples recovered from the firearms are of a sufficient quality to be used for comparison purposes with the DNA the government seeks to obtain from the defendants, there is nothing to suggest that compelling defendants’ DNA will lead to probative evidence in this case.”); United States v. Pakala, 329 F. Supp. 2d 178, 181 (D. Mass. 2004) (holding, on a motion for an order to compel, that individuals should not “be subject to even the minimal intrusion of a swab DNA test unless it is first determined that any substance found on the firearm(s) has yielded a sufficient DNA profile for comparison”); United States v. Robinson, No. 11-CR0325, 2011 WL 7563020, at *3 (D. Minn. Dec. 2, 2011) (finding no probable cause for taking a DNA sample where “the Government has provided no evidence that it has as yet even tested the firearm at issue in this case to see whether there is any retrievable DNA evidence to which any comparison of the DNA sample seized from Defendant can be made,” because “the Fourth Amendment forbids intrusions on the mere chance that desired evidence might be obtained”) (internal quotation marks and citation omitted); United States v. Jennings, No. 21-cr-60193, 2021 WL 5235292, at *8 (S.D. Fla. Nov. 10, 2021) (“[B]ecause the DNA sample from the firearm had not yet been analyzed, there was no probable cause to believe that the DNA from Defendant would yield relevant evidence.”); with, e.g., United States v. Harrison, 683 F. Supp. 3d 184, 205 (N.D.N.Y. 2023) (Hurd, J.) (“The fact that other magistrates in other judicial districts might have wanted to see a bit more from the search warrant affiant before signing off on a warrant does not vitiate the probable cause determination made in this case.”); United States v. Sedillo, 297 F. Supp. 3d 1155, 1181 (D.N.M. 2017) (“[T]he Fourth Amendment does not require the United States to confirm that evidence collected—in this case, the clothing—will yield a viable DNA sample before swabbing the arrestees for DNA,” because “[p]robable cause is not a

question—whether a search warrant application can establish probable cause

without identifying usable DNA samples taken from physical evidence linked to

the alleged crime—is one of ﬁrst impression for federal appellate courts. Leeper

asks us to resolve it conclusively by adopting a bright line rule that “[a]bsent any

comparison DNA, there is no way to establish probable cause that a suspect’s DNA

will be evidence of anything.” Appellant’s Br. at 23. But “[p]robable cause is a

ﬂuid concept turning on the assessment of probabilities in particular factual

contexts, and as such is not readily, or even usefully, reduced to a neat set of legal

rules.” Raymonda, 780 F.3d at 113 (internal quotation marks and citations omitted).

We conclude that demonstrating probable cause to obtain a DNA sample

will not always require the government to identify speciﬁc DNA samples for

comparison. Nor will it never require such identiﬁcation. The probable cause

determination in these cases depends on any number of factors, including whether

there is physical evidence that could link a particular suspect to a crime, how much

granular inquiry.”); United States v. Burkhalter, No. 4:18-CR-00036-1, 2023 WL 2653388, at *5 (W.D. Miss. Mar. 27, 2023) (noting that “courts appear to be split on the issue” and finding “the reasoning set forth in United States v. Sedillo . . . persuasive”); In re Search Warrant, No. 24-MJ-02376, 2024 WL 1174726, at *7 (S.D. Fla. Mar. 18, 2024) (finding it sufficient that there was “probable cause to believe that [the defendant] possessed (and then tossed) the firearm, and that he may have deposited usable DNA on the firearm, ammunition, and holster”) (emphasis added).

physical evidence there is, the type of physical evidence, and the like.

Here, there was probable cause to search Leeper’s DNA. The search warrant

application identiﬁed eight shell casings, seven projectiles, and multiple cut zip

ties recovered at the scene of Chavez’s homicide, as well as the rental car and

Chavez’s body itself, any or all of which could have contained usable DNA

samples against which to test Leeper’s DNA. Indeed, Leeper acknowledges that

the government’s contention that “Leeper would have had ‘ample opportunity to

deposit touch DNA’ . . . is true.” Appellant’s Reply Br. at 18. The supporting

aﬃdavit does not establish with certainty that there would be a sample against

which to compare Leeper’s DNA, but that is not what the Fourth Amendment

requires. “While probable cause requires more than a ‘mere suspicion,’ of

wrongdoing, its focus is on ‘probabilities,’ not ‘hard certainties.’” Walczyk v. Rio,

496 F.3d 139, 156 (2d Cir. 2007) (internal citations omitted). Probable cause

“requires only such facts as make wrongdoing or discovery of evidence thereof

probable.” Id. at 157. The issuing court had a substantial basis for its determination

that the plethora of physical evidence recovered from the scene made it probable

that obtaining a DNA sample from Leeper would lead to the discovery of evidence

of a crime. Accordingly, we conclude that the district court properly denied

Leeper’s motion to suppress on this basis.

b. Procedural Due Process

Leeper also challenges the warrant on a procedural ground: that he was

denied procedural due process because the oﬃcers obtained an ex parte warrant to

take a sample of his DNA, using a buccal swab, without providing him advance

notice or an opportunity to be heard. “With respect to a claimed due process

violation, we review the district court’s factual determinations for clear error,

while the constitutional signiﬁcance of those ﬁndings, including the ultimate

determination of whether due process has been violated, is reviewed de novo.”

United States v. Epskamp, 832 F.3d 154, 160 (2d Cir. 2016) (alteration adopted)

(internal quotation marks and citation omitted).

Leeper broadly argues that the uniquely revealing nature of DNA implicates

core privacy interests, necessitating a pre-deprivation hearing. Moreover, Leeper

asserts that, “had [he] been aﬀorded notice and a chance to be heard, it is unlikely

that the judge would have issued the search warrant for his DNA because it would

have realized, through an adversarial proceeding, that Sergeant Williams’

supporting aﬃdavit failed to state probable cause that the DNA would yield

evidence of a crime.” Appellant’s Br. at 28–29.

In advancing this argument, Leeper principally relies on Mathews v. Eldridge,

424 U.S. 319 (1976), which directs courts, in determining whether procedural

requirements related to the deprivation of property or liberty interests are

constitutionally suﬃcient, to apply a three-part balancing test that weighs the

following factors:

First, the private interest that will be aﬀected by the oﬃcial action;

second, the risk of an erroneous deprivation of such interest through

the procedures used, and the probable value, if any, of additional or

substitute procedural safeguards; and ﬁnally, the Government’s

interest, including the function involved and the ﬁscal and

administrative burdens that the additional or substitute procedural

requirement would entail.

Id. at 335.

As an initial matter, the government argues that Mathews has no application

to Fourth Amendment challenges. Leeper counters that the Mathews “test is

applied to myriad cases that require balancing public and private interests in

determining whether suﬃcient process was granted.” Appellant’s Reply Br. at 3.

To be sure, in the criminal context, we have applied the Mathews test in

determining that a defendant found guilty after trial could not be detained

pending appeal based on an ex parte showing by the government. See United States

v. Abuhamra, 389 F.3d 309, 318, 332 (2d Cir. 2004). Furthermore, we have applied

the Mathews test in addressing the process that was required before a prosecutor

could retain a vehicle as potential evidence pending a criminal proceeding. See

Krimstock v. Kelly, 464 F.3d 246, 253–55 (2d Cir. 2006) (applying Mathews and

concluding that “no full-dress adversarial hearing is required to review a

prosecutor’s unilateral determination that a vehicle is needed as potential

evidence” and “district attorneys must be permitted to seek retention orders ex

parte so that defendants cannot use the hearings for discovery or to restrict the

prosecution’s theories at trial”).

Notwithstanding the application of Mathews to examine certain detention

and seizure issues in criminal proceedings, search warrants are diﬀerent, from

both a historical and practical standpoint, and the government correctly notes that

“no federal appellate court has held that judicial review of search warrant

applications must comport with the Mathews procedural due process framework

or otherwise has suggested that Mathews plays a role in this context.” Appellee’s

Br. at 52. Indeed, without any reference to Mathews, the Supreme Court

unequivocally held over ﬁve decades ago that, when a law enforcement oﬃcer

applies for a search warrant, the proceeding “is necessarily ex parte, since the

subject of the search cannot be tipped oﬀ to the application for a warrant lest he

destroy or remove evidence.” 6 Franks v. Delaware, 438 U.S. 154, 169 (1978); United

States v. U.S. Dist. Ct. for E. Dist. of Mich., S. Div., 407 U.S. 297, 321 (1972) (“[A]

warrant application involves no public or adversary proceedings: it is an ex parte

request before a magistrate or judge.”); see also Times Mirror Co. v. United States, 873

F.2d 1210, 1213–14 (9th Cir. 1989) (“[O]ur review of the history of the warrant process

in this country indicates that the issuance of search warrants has traditionally been

carried out in secret. Normally a search warrant is issued after an ex parte

application by the government and an in camera consideration by a judge or

magistrate.”). Thus, we have serious doubts as to whether the Mathews test should

be applied at all to potentially impose additional procedural rules beyond what is

required under the Fourth Amendment. See Gerstein v. Pugh, 420 U.S. 103, 125 n.27

(1975) (“The Fourth Amendment was tailored explicitly for the criminal justice

system, and its balance between individual and public interests always has been

thought to deﬁne the ‘process that is due’ for seizures of person or property in

criminal cases, including the detention of suspects pending trial.”); see also

In Winston v. Lee, 470 U.S. 753 (1985), the Supreme Court left open the question of whether “special procedural protections” are warranted under the Fourth Amendment when the search involves “[a] compelled surgical intrusion into an individual’s body for evidence,” such as an order for a suspect to undergo surgery to remove a bullet lodged in his body. Id. at 759, 763 n. 6. No such surgical intrusion is at issue in this case, which involves only the use of a buccal swab.

Abuhamra, 389 F.3d at 328 (rejecting the “view that ex parte submissions at bail

hearings are analogous to ex parte submissions in support of arrest and search

warrants, or wire-tap authorizations” and noting that “[t]he competing interests

at stake in connection with the issuance of warrant and wire-tap authorizations

confer no pre-issuance right to an adversarial hearing on any person”).

However, we need not resolve that issue here because we hold that, even

assuming arguendo that Mathews applies to ex parte warrants for DNA collection

with a buccal swab, the three-part test does not require the government to give

notice and an opportunity to be heard because the government’s compelling law

enforcement interests in being able to obtain ex parte warrants for DNA collection

outweigh an individual’s private interests and the risk of erroneous deprivation in

the absence of that procedure. 7 We address each of the Mathews factors below.

We note that New York state courts have recognized a due process right to notice and an opportunity to be heard when law enforcement seeks a search warrant for an uncharged suspect’s DNA in non-exigent circumstances. See, e.g., People v. Fomby, 103 A.D.3d 28, 29–30 (N.Y. App. Div. 2012) (citing Matter of Abe A., 437 N.E.2d 265 (N.Y. 1982), which concerned a search warrant for an uncharged suspect’s blood sample). However, the New York Court of Appeals has clarified that the suspect’s right to be heard is limited to “the nature of the bodily intrusion to be authorized by, and the evidence to be collected under, the warrant,” and he is not entitled to challenge the probable cause showing in the warrant application, which is what Leeper seeks here. People v. Goldman, 159 N.E.3d 772, 781 (N.Y. 2020); id. (“The constitutional role of the neutral magistrate to determine whether the warrant application set forth probable cause of defendant’s commission of the crime and the factual basis for the DNA comparative evidence set forth in the warrant

i. The Government’s Interest

As our holding rests on the conclusion that the government has overriding

interests in being able to conduct ex parte warrant proceedings for DNA collection

in the context of an ongoing criminal investigation, we begin with this step of the

Mathews test.

It is beyond dispute that the collection and analysis of DNA are critical tools

used by the government to accurately identify individuals responsible for criminal

conduct, and the government has a “compelling interest in ﬁnding, convicting,

and punishing those who violate the law.” Moran v. Burbine, 475 U.S. 412, 426

(1986); see also Schall v. Martin, 467 U.S. 253, 264 (1984) (“The legitimate and

compelling state interest in protecting the community from crime cannot be

application required no supplemental adversarial process. Thus, the method and procedures employed in taking the saliva undoubtedly respected relevant Fourth Amendment standards of reasonableness, and defendant’s claim that the failure to provide him discovery of the extant probable cause and an adversarial hearing nonetheless warrants the invocation of the exclusionary rule is without constitutional basis.”). The court also concluded, because the procedure was constitutionally sufficient, it was “not necessary to address the People’s arguments that Abe A.’s notice procedure preceding the issuance of a search warrant is no longer required for the minimal intrusion occasioned by a buccal swab or that the notice procedure does not apply to a suspect who is in custody.” Id. In any event, federal law, not state law, applies to this federal criminal prosecution. See United States v. Pforzheimer, 826 F.2d 200, 204 (2d Cir. 1987) (“[W]e are persuaded that federal law should apply to this federal criminal prosecution, even though the underlying investigation leading to prosecution was conducted solely by state officials.”).

doubted.”) (internal quotation marks and citation omitted); Nicholas v. Goord, 430

F.3d 652, 669 (2d Cir. 2005) (“There can be little doubt that New York has a strong

government interest in obtaining identifying information from convicted

oﬀenders [through DNA collection] and keeping a record of such information [in

a DNA database].”).

That compelling interest in accurate investigations and prosecutions

obviously includes using DNA analysis to exonerate the innocent. See, e.g., United

States v. Sczubelek, 402 F.3d 175, 185 (3d Cir. 2005) (emphasizing that “DNA samples

will help to exculpate individuals who are serving sentences of imprisonment for

crimes they did not commit and will help to eliminate individuals from suspect

lists when crimes occur”); see also Kaemmerling v. Lappin, 553 F.3d 669, 680 (D.C.

Cir. 2008) (recognizing, in the context of a challenge to the collection and retention

of DNA in a database, that there is a “compelling governmental interest in

accurately and expeditiously solving past and future crimes in order to protect the

public and ensure conviction of the guilty and exoneration of the innocent”).

Often the government cannot advance these compelling interests without

obtaining a search warrant to collect the DNA sample that is necessary for

comparison purposes.

The rationale for the longstanding rule that the government should be able

to submit search warrant applications ex parte is also quite obvious: if notice and

an opportunity to be heard were required prior to a search warrant being issued,

the criminal investigation could be compromised in numerous ways including,

inter alia, by the destruction of evidence or other eﬀorts to obstruct justice, as well

as by one or more targets of the investigation ﬂeeing from potential prosecution.

See Franks, 438 U.S. at 169 (“The pre-search proceeding is necessarily ex parte, since

the subject of the search warrant cannot be tipped oﬀ to the application for a

warrant lest he destroy or remove evidence.”); United States v. Ulbricht, 858 F.3d 71,

107 (2d Cir. 2017) (aﬃrming denial of a request to unseal a document regarding a

grand jury proceeding because “potential co-conspirators might have learned of

the investigation and attempted to intimidate witnesses or destroy evidence”),

overruled on other grounds by Carpenter v. United States, 585 U.S. 296 (2018).

Leeper, although recognizing that “the government has a strong interest in

obtaining DNA evidence,” argues that these compelling reasons for an ex parte

warrant do not apply to the collection of DNA from a suspect because (1) “the DNA

[sought] from the suspect’s body cannot be spoliated, not even if the suspect dies,”

and (2) “the suspect must be informed before the sample is taken from their body,

so the warrant cannot be executed while maintaining a conﬁdential investigation.”

Appellant’s Br. at 28.

These arguments miss the mark. Although the suspect’s DNA cannot be

spoliated and the existence of the criminal investigation is necessarily exposed to

the suspect by the collection of the DNA, there remains a host of means for the

suspect, as well as any co-conspirators, to impede the investigation. In particular,

Leeper overlooks the critical fact that his proposed right to notice and an

opportunity to be heard before the issuance of the warrant would include

providing a copy of the warrant application to the suspect while the investigation

is still pending, or even at its infancy. That application, which must contain

information suﬃcient to establish probable cause to authorize the DNA collection,

could provide the suspect (and anyone else to whom that suspect shares that

information) with conﬁdential details about the witnesses and evidence gathered

so far in the investigation, including grand jury material, as well as potentially

shed light on law enforcement’s theory of the case and knowledge of the role of

any co-conspirators. Armed with this roadmap of the scope and status of the

government’s investigation, the suspect (even if in custody), as well as any coconspirators in the criminal activity (whether known or unknown to law

enforcement), could engage in all types of obstruction of that investigation,

including destroying other non-DNA evidence not yet obtained by law

enforcement and intimidating or tampering with potential witnesses.

Moreover, the suspect (if he is not already in custody) could ﬂee the

jurisdiction once he is given notice of the search warrant application, thereby

thwarting the collection of the DNA from him or any future criminal prosecution.

Even if the suspect is in custody, any non-incarcerated co-conspirators would have

their own opportunity to ﬂee, especially if the warrant application were made

known to them and revealed that the investigation was well-developed and

additional arrests were imminent. See Application of Dow Jones & Co., Inc., 842 F.2d

603, 611 (2d Cir. 1988) (“[T]argets learning of their possible indictment might ﬂee

or tamper with . . . witnesses.”). Indeed, these compelling law enforcement

interests in protecting the conﬁdential details of an ongoing criminal investigation

are precisely why government applications for search warrants typically remain

sealed until after the target is arrested.

Other courts have similarly recognized the compelling government interests

in maintaining the conﬁdentiality of search warrant applications while an

investigation is pending. For example, in Matter of EyeCare Physicians of America,

100 F.3d 514 (7th Cir. 1996), companies whose premises were searched pursuant to

warrants ﬁled a motion to have the search warrant applications and aﬃdavits

unsealed to allow them to assess whether to challenge the government’s search.

Id. at 515. In aﬃrming the denial of the motion, the Seventh Circuit noted that

disclosure of the aﬃdavits would breach the secrecy of the grand jury

investigation and outlined other potential adverse ramiﬁcations from such a

disclosure:

Additional consequences in disclosing the sealed aﬃdavits include:

the identity of unnamed subjects not yet charged would be revealed;

there may be mistaken notions concerning who might and might not

be cooperating with the government or who may be subjects; there

may be misunderstandings about the parameters of the government’s

investigation; the privacy of the innocent and the implicated would

be threatened; and the cooperation of present and potential witnesses

could be compromised or inﬂuenced. . . . We agree with the

magistrate judge and the district court that disclosure of the aﬃdavits

might very likely impair the ongoing criminal investigation.

Id. at 519; see also Media Gen. Operations v. Buchanan, 417 F.3d 424, 429 (4th Cir. 2005)

(holding that there was no right to view the sealing orders for the search warrant

prior to the execution of the warrant and emphasizing that “[a] rule to the contrary

would endanger the lives of oﬃcers and agents and allow the subjects of the

investigation to destroy or remove evidence before the execution of the search

warrant”); In re Search Warrant for Secretarial Area Outside Oﬀ. of Gunn, 855 F.2d 569,

573 (8th Cir. 1988) (“[T]he very objective of the search warrant process, the seizure

of evidence of crime, would be frustrated if conducted openly.”). It is likewise not

hard to imagine how one or more of these adverse consequences to an ongoing

criminal investigation could potentially result from the disclosure of a search

warrant application to collect DNA from a suspect, even when the suspect is in

custody.

In addition to the damage that could arise from disclosure of the details of

the search warrant application, the delay that would inevitably result from preseizure notice and an opportunity to be heard could similarly impede criminal

investigations where time is often of the essence and any delay could jeopardize

public safety. See generally In re Sealed Case, 77 F.4th 815, 828 (D.C. Cir. 2023) (“Time

is of the essence when the government seeks evidence needed in a criminal case,

so there may be little opportunity to fully litigate a substantial constitutional claim

while holding in abeyance the execution of a search warrant.”). Importantly, in

many instances, the delay could be substantial because a suspect may need time

to retain an attorney, the attorney will then need time to prepare a motion to which

the government will need to respond, and the court may be required to hold an

evidentiary hearing. As the Supreme Court has explained, “[t]his Court has

recognized, on many occasions, that where a State must act quickly, or where it

would be impractical to provide predeprivation process, postdeprivation process

satisﬁes the requirements of the Due Process Clause.” Gilbert v. Homar, 520 U.S.

924, 930 (1997) (collecting cases); see also Parratt v. Taylor, 451 U.S. 527, 539 (1981)

(“[E]ither the necessity of quick action by the State or the impracticality of

providing any meaningful predeprivation process, when coupled with the

availability of some meaningful means by which to assess the propriety of the

State’s action at some time after the initial taking, can satisfy the requirements of

procedural due process.”); accord Catanzaro v. Weiden, 188 F.3d 56, 61–63 (2d Cir.

1999). Those are precisely the circumstances present here.

Although Leeper notes that the government sometimes opts to proceed by

way of a court order to extract DNA with notice to the suspect when that suspect

is already in custody, that voluntary decision by the government—in some

circumstances where they have determined that obstruction of justice and ﬂight

are not substantial risks in that particular investigation or prosecution—does not

support the argument that the government should be required to give notice in any

such situation. See Times Mirror Co., 873 F.2d at 1217 (concluding that “the fact that

search warrants and supporting aﬃdavits are often ﬁled with the district court

without seal . . . merely describes a practice in cases where the government

presumably believes secrecy is unnecessary” and does not demonstrate that

sealing is never warranted). For example, the government may voluntarily opt to

seek a court order to collect DNA with notice (rather than seek an ex parte search

warrant) when an incarcerated defendant has already been arrested for the crime,

is believed to have acted alone in connection with the crime, and is either already

aware of the details of the investigation from discovery already provided to his

counsel in the criminal case or is not in a position to destroy the evidence or

intimidate the witnesses supporting his current prosecution. Those circumstances

are a far cry from other situations where the risks to the investigation from

disclosure of the warrant application remain high at the time of the DNA

collection, such as where an investigation is far from complete, its details are

unknown, and/or co-conspirators remain at large.

Leeper also suggests that the government should be required, in each

individual situation involving a request to extract a person’s DNA, to demonstrate

that there are suﬃcient law enforcement reasons to justify an ex parte application.

See Appellant’s Reply Br. at 14 (“[I]f . . . the government has a reason to make the

application ex parte, then it can explain the reasons at that time; but that is not

grounds to allow, by default, all requests to extract a person’s DNA to be made ex

parte and without prior notice to them.”). In other words, under Leeper’s

approach, when the government seeks an ex parte search warrant to collect DNA

from a suspect, the government should be required in each case to “present[]

exigent circumstances warranting the postponement of notice and the opportunity

for an adversarial hearing.” United States v. 4492 S. Livonia Rd., 889 F.2d 1258, 1265

(2d Cir. 1989). We disagree.

To be sure, “[t]he determination of whether one is entitled to a predeprivation hearing is fact-speciﬁc, as ‘due process is ﬂexible and calls for such

procedural protections as the particular situation demands.’” Ciambriello v. Cnty.

of Nassau, 292 F.3d 307, 319 (2d Cir. 2002) (quoting Mathews, 424 U.S. at 334).

However, for the reasons discussed above, it is clear that requiring the government

to demonstrate exigent circumstances warranting an ex parte search application in

each individual case where DNA collection is sought from a suspect (even if such

a rule is limited to incarcerated suspects) is unworkable and insuﬃcient to protect

the government’s compelling interest in, inter alia, maintaining the conﬁdentiality

of its search warrant application, especially because it is often diﬃcult for the

government to identify and articulate at the time of that application exactly how

or where a target or his co-conspirators could undermine the investigation if

provided with the search warrant application. Indeed, law enforcement oﬃcers

routinely obtain ex parte search warrants to gather all types of evidence that belong

to (or implicate the privacy interests) of an incarcerated individual, including from

his or her home, car, rental space in a storage facility, computer, cellphone, email

account, or social media accounts. No court has suggested, nor does Leeper even

suggest, that the government should be required to provide suﬃcient justiﬁcation

for the ex parte nature of the application in each and every one of those situations

simply because the individual is incarcerated and thereby may not be able to

personally undermine the investigation if he is provided with notice and an

opportunity to be heard before the issuance of the warrant. Instead, in each of

those situations, the compelling law enforcement reasons for maintaining the

secrecy of the investigation and the often unknowable risks of disclosing the

application to the target of the investigation, even when the target is incarcerated,

would be undermined by any such case-by-case requirement. All of those

compelling justiﬁcations supporting ex parte warrants in those situations apply

with equal force to a search warrant that seeks the collection of DNA from a

suspect like Leeper, even when he is in custody. In short, under Mathews, the

particular demands of the search warrant application process, including the

practical realities and exigencies of ongoing criminal investigations and the

importance of maintaining the conﬁdentiality of search warrant applications

during that investigation, support allowing the government to seek a search

warrant for the collection of a DNA sample from a suspect without providing that

suspect with notice and an opportunity to be heard at the time of the warrant

application.

ii. Leeper’s Private Interests

With respect to the Mathews factor that considers the private interests

impacted by the government’s action, Leeper argues that DNA is diﬀerent than

other forms of evidence routinely seized from a target in that he has an

“exceptionally high interest in the privacy of his genetic makeup” as once it is

extracted and “posted on government databases,” “it is forever in the public

sphere.” Appellant’s Br. at 32–33. Leeper further asserts that his DNA sample

could be used to reveal his “medical history, family history, and aspects of [his]

sexual history”—i.e., intimate personal details that should be aﬀorded a high

degree of privacy. Id. at 33. As set forth below, we conclude that these privacy

interests are insuﬃcient to outweigh the government’s compelling justiﬁcations

for obtaining ex parte warrants to collect DNA evidence.

As a threshold matter, it is important to note that the ex parte warrant in this

case only authorized the collection of DNA via a buccal swab. The Supreme Court

has held that buccal swabs amount to only a “negligible” intrusion on one’s

person. Maryland v. King, 569 U.S. 435, 446 (2013) (describing a buccal swab as a

“gentle process” that “involves but a light touch on the inside of the cheek”).

Indeed, we have noted that, even an intrusion to take a blood sample, “while

subject to the Fourth Amendment, is minimal,” and “where inmates are routinely

subject to medical procedures, including blood draws, and where their expectation

of bodily privacy, while intact, is diminished, the intrusiveness of a blood draw is

even further minimized.” Goord, 430 F.3d at 669 (internal citations omitted).

We recognize that, by testing the saliva sample from the buccal swab, the

government will have access to the suspect’s DNA, which can reveal intimate

details about him. This access to such details, however, does not necessarily lead

to the conclusion that a special constitutional rule is required with respect to the

collection and analysis of that type of evidence in a criminal investigation. For

example, in the context of a Fourth Amendment analysis, numerous courts have

held that, if law enforcement obtains an individual’s saliva (or some other bodily

material) that has been abandoned in a public place, no search warrant is required

before the DNA from that sample can be analyzed—notwithstanding the intimate

details that could be revealed from it. See, e.g., Emerson v. Kelly, No. 1:14-cv-00809,

2015 WL 3968250, at *14 (N.D. Ohio June 30, 2015) (“[A] person has no reasonable

expectation of privacy in his or her DNA proﬁle extracted from a lawfully obtained

DNA sample.”) (internal quotation marks and citation omitted); United States v.

Scott, No. 10-00027-01-CR, 2011 WL 5387601, at *6 (W.D. Mo. Oct. 3, 2011) (“[T]he

DNA obtained from the cup Defendant left on the coﬀee table should not be

suppressed as the warrantless search of abandoned property does not violate the

Fourth Amendment.”); see also United States v. Hicks, No. 2:18-cr-20406, 2020 WL

7704556, at *4 (W.D. Tenn. May 27, 2020) (noting that “[o]ther courts have found

one’s abandonment of an item containing his or her DNA suﬃcient to permit the

government to conduct forensic analysis on that sample without a warrant”)

(collecting cases). In any event, for due process purposes, we conclude that any

additional privacy interests that a suspect in a criminal investigation has in the

DNA material of a sample lawfully obtained pursuant to a search warrant do not

suﬃciently outweigh the compelling justiﬁcations that exist, as discussed supra,

for not requiring law enforcement to give that suspect notice and an opportunity

to be heard in connection with the search warrant application for that sample.

Although Leeper suggests that his proposed exception to the general rule

that ex parte search warrants are permitted would be a narrow one because of the

unique nature of DNA and the personal details revealed by its examination, we

have our doubts about the narrowness of the rule he proposes. Indeed, if the

ability of a search warrant to reveal intimate details of a person’s life were

suﬃcient under the Due Process Clause to prompt a requirement of notice and an

opportunity to be heard at the time of the search warrant application, then many

types of search warrants would undoubtedly fall within that rule. For instance, in

Riley v. California, 573 U.S. 373 (2014), the Supreme Court emphasized that

cellphones are functionally “a digital record of nearly every aspect of [a person’s]

li[fe]—from the mundane to the intimate.” Id. at 395. Cellphones may contain

intimate conversations with loved ones, GPS locations, medical and business ﬁles,

and real-time monitoring of health statistics, among other revealing information.

Id. at 394–96, 403. Moreover, since the decision in Riley over ten years ago,

technology has only evolved and the types and volume of information that may

be stored on an electronic device has increased exponentially. 8 Thus, electronic

devices may hold just as much “vast and sensitive” information—if not more—

than a DNA analysis. Appellant’s Br. at 31. Yet adopting Leeper’s reasoning

would seemingly prevent law enforcement from proceeding with an ex parte

warrant application to obtain the contents of a cellphone already in police custody

and owned by an incarcerated person. No court has suggested that such a rule

exists with respect to cellphones, and, in our view, Leeper’s reasoning would

fundamentally change the warrant application process for many types of searches,

particularly for suspects who are incarcerated, and run the risk of severely

impeding law enforcement across a broad spectrum of investigations.

Finally, with respect to his private interests, Leeper points out that the

invasion of privacy is magniﬁed with respect to the collection of DNA because it

is maintained in a public database. We have acknowledged, in connection with

the extraction and analysis of convicted felons’ blood for DNA-indexing purposes

pursuant to a statute, that DNA collections constitute multi-tiered “intrusions” on

the subject of the collection—a ﬁrst “physical intrusion” occurs when the DNA

8 For example, there are now applications available that allow a person to upload and analyze their DNA data to their cellphone, which would likewise be available to law enforcement during a cellphone search. See What we do, GENOMAPP (last visited March 9, 2026), https://genomapp.com/en/what-we-do/ [https://perma.cc/R5GL-YZSJ].

sample is actually taken, and a second occurs during the “analysis and

maintenance of [the] DNA information,” which we have explained is a

“potentially a far greater intrusion than the initial extraction,” since the obtaining

entity may “maintain[] DNA records indeﬁnitely.” Goord, 430 F.3d at 669–70

(upholding New York’s DNA database statute against a Fourth Amendment

challenge).

Here, although we likewise recognize the privacy concerns implicated by

the ability of law enforcement to maintain the DNA permanently in a national

database, Leeper overlooks the substantial safeguards that exist with respect to

those concerns. As a threshold matter, contrary to Leeper’s suggestion, the

collection of a DNA sample does not necessarily lead to nationwide publication of

that sample in the database. As the government correctly points out, it is only after

a conviction that maintenance on the national index would be required. See 34

U.S.C. § 40702(a)(1)–(2); see generally United States v. Amerson, 483 F.3d 73, 86 (2d

Cir. 2007) (explaining that, once a defendant is convicted, the “expectation of

privacy in his or her identity is severely diminished”). Furthermore, there are

numerous safeguards governing the use and maintenance of DNA information

within the national index. For example, DNA information may only be disclosed

in limited circumstances and to a limited number of actors: (1) to criminal justice

agencies for law enforcement purposes; (2) in judicial proceedings; (3) for criminal

defense purposes; and (4) for population statistics databases and research, only if

personally identiﬁable information is removed. 34 U.S.C. § 12592(b)(3). Consistent

with these protections, if the subject of a DNA analysis is exonerated, acquitted, or

the charges are dropped, DNA information may be expunged from the database.

34 U.S.C. § 12592(d)(1)–(2). Accordingly, it is not the case, as Leeper argues, that

once DNA is collected, pursuant to an ex parte warrant or otherwise, that a

suspect’s DNA “is forever in the public sphere” without any safeguards. 9

Appellant’s Br. at 33; see Goord, 430 F.3d at 671 (“Given the limits imposed on the

collection, analysis, and use of DNA information by the statute, . . . the intrusion

The ex parte warrant for Leeper’s DNA collection was issued by a state judge in Cortland County, New York. That the warrant originated in the state judicial system does not impact our analysis with respect to these procedural safeguards. In Goldman, the New York Court of Appeals emphasized that “[New York law] demands an accredited state laboratory conform to the national DNA index system in developing the DNA profile from limited loci and imposes a similar duty to maintain confidentiality of the results of DNA testing to avoid unwarranted disclosures.” 159 N.E.3d at 780 (citing, inter alia, New York Executive Law §§ 995-c, 995-d). Indeed, the court concluded, “[a]ssuming the applicability of those significant statutory safeguards, there is no need for an adversarial hearing to determine whether the collection of a DNA sample amounts to an unreasonable invasion of privacy in a particular case.” Id. Moreover, when DNA information collected by a state or local criminal justice agency is included in the national index, the federal restrictions regarding use and disclosure apply. See 34 U.S.C. § 12592(b)(3).

on privacy eﬀected by the statute . . . is insuﬃcient to outweigh the state’s strong

interest in maintaining a DNA index.”); Roe v. Marcotte, 193 F.3d 72, 80 (2d Cir.

1999) (ﬁnding suﬃcient safeguards in a DNA statute that “restricts access to and

secures the conﬁdentiality of the results and provides for the expungement of the

results from the data bank upon the reversal or dismissal of a conviction”) (internal

citations omitted).

In sum, under the Mathews test, we conclude that Leeper’s private interests

in his DNA do not outweigh the government’s compelling interests in conducting

eﬀective law enforcement investigations that are aided by the ability to obtain ex

parte search warrants for DNA collection from a suspect, even when that suspect

is incarcerated.

iii. Risk of Erroneous Deprivation

Finally, we examine the Mathews factor that addresses the risk of erroneous

deprivation—i.e., the likelihood that holding pre-deprivation hearings prior to the

issuance of DNA warrants would reduce the chance of erroneous outcomes. See

Mathews, 424 U.S. at 335. As set forth below, we conclude that this factor does not

support a requirement of notice and an opportunity to be heard before a search

warrant for DNA collection is considered.

Importantly, even in the absence of any ability by a suspect to challenge the

issuance of a search warrant, the Fourth Amendment guards against unreasonable

searches and seizures by requiring the government to demonstrate probable cause

to a judicial oﬃcer before the warrant can be issued. U.S. C ONST . amend. IV. The

Supreme Court has explained that the “long-prevailing constitutional standards

of probable cause embod[y] the best compromise that has been found for

accommodating the often-opposing interests in safeguarding citizens from rash

and unreasonable interferences with privacy and in seeking to give fair leeway for

enforcing the law in the community’s protection.” Dunaway v. New York, 442 U.S.

200, 208 (1979) (alterations adopted) (internal quotation marks and citation

omitted). Thus, “an ex parte probable cause determination before a judicial oﬃcer

reduces the possibility of an erroneous deprivation.” 4492 S. Livonia Rd., 889 F.2d

at 1265.

Moreover, the risk of erroneous deprivation is further minimized by the

exclusionary rule, which functions to “deter future Fourth Amendment

violations.” Davis v. United States, 564 U.S. 229, 248 (2011); see also Abuhamra, 389

F.3d at 328 (distinguishing ex parte submissions at bail hearings from ex parte

submissions in support of warrants and wire-tap applications because “[o]nce

such orders are executed . . . the ex parte submissions are generally unsealed—in

the case of the arrest and search warrants, usually immediately—and parties

whose liberty or property interests are aﬀected are aﬀorded opportunities to

challenge the legality of the actions”); United States v. Smith, 575 F. Supp. 3d 542,

555 (E.D. Pa. 2021) (holding that, because the police obtained the defendant’s DNA

sample in violation of the Fourth Amendment, “the exclusionary rule compel[led]

the suppression of any evidence of Defendant’s DNA sample and the forensic

analyses derived from it as the tainted fruit of unlawful government conduct”)

(internal quotation marks and citation omitted). Here, following his indictment in

federal court, Leeper had the opportunity to challenge the probable cause

determination for the issuance of the warrant which, as discussed supra, the district

court correctly rejected.

These safeguards are suﬃcient under these circumstances to protect a

suspect who is the subject of DNA collection pursuant to an ex parte search warrant

from a violation of his Fourth Amendment rights in connection with the issuance

of the warrant or an erroneous outcome in his criminal proceeding. See generally

United States v. Grubbs, 547 U.S. 90, 99 (2006) (“The Constitution protects property

owners not by giving them license to engage the police in a debate over the basis

for the warrant, but by interposing, ex ante, the deliberate, impartial judgment of a

judicial oﬃcer . . . between the citizen and the police, and by providing, ex post, a

right to suppress evidence improperly obtained and a cause of action for

damages.”) (internal quotation marks and citation omitted).

Leeper again argues that a diﬀerent rule is required in the context of DNA

collection because the deprivation resulting from any unconstitutional action by

law enforcement is more damaging when DNA is collected, as compared to other

types of searches. We are unpersuaded. Neither the Supreme Court nor any other

circuit court has ever suggested that the ex parte process for obtaining of search

warrants should be abandoned because the searches may involve substantial

bodily intrusions, such as body cavity searches, see, e.g., Sloley v. VanBramer, 945

F.3d 30, 40 (2d Cir. 2019), or the collection of evidence from an individual’s

residence, United States v. Sandalo, 70 F.4th 77, 79 (2d Cir. 2023), or a cellphone,

Riley, 573 U.S. at 403, and we can discern no reason to depart from that process

where the search involves the collection of a DNA sample with a buccal swab for

the purposes of DNA analysis in a criminal investigation.

* * *

In sum, under the Mathews test, we conclude that the government’s

compelling interests in the conﬁdentiality of the search warrant application for the

collection of a suspect’s DNA sample during an ongoing investigation are

suﬃciently strong—even when the suspect is incarcerated—to outweigh the

private interests implicated by that search. Moreover, the existing procedural

safeguards for an ex parte application, as well as the ability of the suspect in any

subsequent criminal proceeding to challenge any evidence seized pursuant to the

warrant, are suﬃcient to guard against the risk of erroneous deprivation.

Therefore, even assuming arguendo that the Mathews test applies to ex parte search

warrants for the collection of a DNA sample from a suspect via a buccal swab, the

government is not required under Mathews to provide notice and an opportunity

to be heard in connection with that warrant application, whether or not that

suspect is already in custody. Accordingly, the lack of notice to Leeper in

connection with his search warrant was not a constitutional violation, and it

provides no basis to disturb his conviction.

II. Vehicle Inventory Search

Finally, Leeper challenges the hold and related search of his vehicle, arguing

that the fruits of this search should be suppressed. Leeper’s challenge fails because

the oﬃcers’ decision to hold his car did not violate the Fourth Amendment.

When considering similar questions, “[s]ome courts have concluded that

there are two inquiries: ﬁrst, whether the impoundment of a car is reasonable; and

second, if so, whether the subsequent search of the car after the impoundment is

reasonable.” United States v. Lyle, 919 F.3d 716, 730 n.2 (2d Cir. 2019). This case

involves only the former question. Leeper does not challenge the CCSO policy

requiring an inventory search for vehicles that are properly impounded or held,

nor does he challenge the decision to search the vehicle itself as unreasonable.

Leeper argues only that the decision to hold his truck, which in turn triggered the

search, was unreasonable and pretextual—not that conducting an inventory

search was independently unreasonable once that decision had been made. As in

Lyle, where the defendant “challenged only the impoundment and not the

subsequent search of the rental vehicle,” we “need not reach the second inquiry.”

Id.

Turning then to the question whether the oﬃcers’ decision to hold Leeper’s

vehicle was reasonable, we start with the well-established notion “that police have

the authority, despite the absence of a warrant, to seize and remove from the

streets automobiles in the interests of public safety and as part of their community

caretaking functions—an authority that is beyond reasonable challenge.” Id. at

728. “[U]nder this community caretaking exception to the warrant requirement,

police oﬃcers may exercise their discretion in deciding whether to impound a

vehicle, so long as that discretion is exercised according to standard criteria and

on the basis of something other than suspicion of evidence of criminal activity.”

Id. (internal quotation marks and citation omitted).

We have consistently held that oﬃcers’ decisions to seize and remove

vehicles were reasonable in circumstances where, due to arrests, suspended

licenses, or other reasons, no driver would be available to remove the vehicle from

its location. In Lyle, where the car’s driver and sole occupant had a suspended

license, this Court reasoned that “by impounding the vehicle, the oﬃcer ensured

that the rental vehicle was not left on a public street in a busy midtown Manhattan

location where it could have become a nuisance or been stolen or damaged and

could have become illegally parked the next day.” Id. at 731. The same was true

in United States v. Lopez, where “the circumstances called for the impoundment of

[Lopez’s] car, as Lopez was arrested for driving it while intoxicated.” 547 F.3d 364,

372 (2d Cir. 2008).

The same reasoning applies here. As the district court found, Leeper’s

vehicle had an expired registration, such that no one could lawfully drive it away;

even if someone could, neither Leeper nor Rodriguez had a valid license. In these

circumstances, the oﬃcers’ decision to hold the truck was reasonable.

Leeper’s arguments to the contrary are unpersuasive. First, Leeper argues

that the decision to impound his vehicle was unreasonable because the CCSO

oﬃcers did not adhere to their standardized written procedures. This is neither

true nor dispositive. The district court found that “there is uncontradicted

evidence that Wright complied with standard policy.” App’x at 184. Although

Leeper urges a diﬀerent interpretation of the policy, he provides no reason to

disturb the district court’s ﬁnding, which was supported by Oﬃcer Wright’s

testimony about the policy. And regardless, “[w]hile the existence of and an

oﬃcer’s adherence to a standardized criteria may be helpful in evaluating the

reasonableness of an impoundment, we decline to adopt a standardized

impoundment procedure requirement.” Lyle, 919 F.3d at 731.

Next, Leeper seeks to distinguish this case from Lyle and Lopez, noting the

undisputed fact that his truck was parked in a commercial parking lot—not on a

public street, as in Lyle and Lopez. That is true, but again it is not dispositive. Our

inquiry does not turn on any one individual fact; “the touchstone of the Fourth

Amendment is reasonableness, which, in turn, is measured in objective terms by

examining the totality of the circumstances.” Id. (internal quotation marks and

citation omitted). Here, as noted above, no one on the scene could lawfully drive

the vehicle away from its location. Although it was in a private parking lot, Leeper

had not sought permission to leave the truck there, there was no telling how long

it would remain there, and it was certainly reasonable to conclude it might have

“become a nuisance or been stolen or damaged.” Id.

Last, Leeper claims the decision to impound the truck was pretextual and

was simply an excuse to search it. But the sole basis for that claim is Leeper’s ipse

dixit that there was no community caretaking reason to impound the truck, which

we have already rejected.

In sum, we hold that the oﬃcers’ decision to hold the truck, which had

neither a valid registration nor any driver who could remove it legally, was

reasonable under the Fourth Amendment, and the fruits of the accompanying

search need not be suppressed.

CONCLUSION

For the foregoing reasons, we AFFIRM the judgment of the district court.

23-3110-cr

United States v. Leeper

RICHARD J. SULLIVAN, Circuit Judge, concurring in the judgment:

Although I agree with the majority’s ultimate outcome, I write separately

because I believe that Mathews v. Eldridge, 424 U.S. 319 (1976), is inapplicable to

search warrants. I would hold as much, without assuming arguendo that Mathews

does apply and then conducting the procedural due-process analysis that it

requires.

It is well established that the standards governing searches and seizures are

derived from the Fourth Amendment. The Supreme Court reached that

conclusion more than fifty years ago. See Gerstein v. Pugh, 420 U.S. 103, 125 n.27

(1975). Holding that the Fourth Amendment is “tailored explicitly for the criminal

justice system,” the Court emphasized that only this Amendment’s “balance

between individual and public interests” could define the “process that is due” for

searches and seizures involving criminal defendants. Id. Indeed, alternate analytic

frameworks developed in the context of civil deprivations – such as Mathews’s

due-process balancing test – are “irrelevant in the wholly different context of the

criminal justice system.” Id. (emphasis added). The reason is simple: the Fourth

Amendment’s original and enduring role is to “safeguard” citizens “from

interferences with privacy and from unfounded charges of crime” while giving “fair leeway” to the government to “enforc[e] the law in the community’s

protection.” Brinegar v. United States, 338 U.S. 160, 176 (1949); see also Gerstein, 420

U.S. at 125 n.27 (“The Fourth Amendment probable cause determination is . . . the

first stage of an elaborate system, unique in jurisprudence, designed to safeguard

the rights of those accused of criminal conduct.”). In other words, because the

Fourth Amendment already strikes the proper balance between the public and

private interests at stake in government searches, there is no need for additional

balancing under the Due Process Clause.

In the context of search-warrant applications specifically, the Supreme

Court has affirmed the constitutionality of ex parte proceedings in every case in

which it has considered the question. In United States v. United States District Court

for the Eastern District of Michigan, for example, the Court underscored that a

search-warrant application is an “ex parte request before a magistrate or judge”

involving “no public or adversary proceedings.” 407 U.S. 297, 321 (1972). That

same description appeared in Franks v. Delaware, where the Court reiterated that,

as a general matter, search-warrant proceedings are “necessarily ex parte, since the

subject of the search cannot be tipped off to the application for a warrant lest he

destroy or remove evidence.” 438 U.S. 154, 169 (1978). Together, both cases leave

no doubt that the requirements of the Fourth Amendment – even when met ex

parte – constitute all the “process that is due” when the government applies for a

search warrant. Gerstein, 420 U.S. at 125 n.27 (internal quotation marks omitted).

Rather than holding that the Fourth Amendment alone governs searchwarrant applications – and that it clearly countenances ex parte proceedings – the

majority’s opinion entertains the idea that Mathews’s procedural due-process

framework could modify or even trump the Fourth Amendment analysis. See Maj.

Op. at 16–17. While admitting that “search warrants are different” and that it has

“serious doubts as to whether the Mathews test should be applied,” the majority

nonetheless decides that it “need not resolve that issue here” because “even

assuming arguendo that Mathews applies to ex parte warrants for DNA collection

with a buccal swab, . . . the government’s compelling law enforcement interests . . .

outweigh an individual’s private interests.” Id. at 17–18. To justify its decision to

leave that issue for another day, the majority cites two cases that it believes lend

credence to the view that Mathews may apply in search-warrant cases. See id. at

16–17. But neither decision stands for that proposition.

The first, United States v. Abuhamra, distinguishes between (i) proceedings to

determine whether a defendant should be detained pending appeal – a context in

which we did apply Mathews – and (ii) search-warrant applications, in which we

clarified that there is “no pre-issuance right to an adversarial hearing [for] any

person.” 389 F.3d 309, 328 (2d Cir. 2004). Abuhamra, in other words, reaffirmed the

principle that the Fourth Amendment supplies all the “process that is due” in

applications for search warrants. Gerstein, 420 U.S. at 125 n.27 (internal quotation

marks omitted).

The second case cited by the majority, Krimstock v. Kelly, concerned

prosecutors’ retention of private vehicles as evidence in potential criminal

proceedings against the drivers – though not necessarily the owners – of those

vehicles. 464 F.3d 246, 253 (2d Cir. 2006). Although we did apply Mathews in

Krimstock, we did so only because the case “involve[d] the deprivation of

property” affecting challengers who might be “innocent owner[s] who [were] no[t]

part[ies] to the criminal proceeding[s].” Id. at 254. Noting that it would be

“redundant” and “inconsistent” to apply the “vaguer notion of ‘due process’” to

“criminal proceedings” governed by the Bill of Rights, we explained that Mathews

was relevant exclusively because neither party was challenging “an underlying

criminal proceeding or the procedural rights due [a] criminal defendant.” Id. Put

simply, Krimstock is a deprivation of property case, not a criminal procedure or

search-warrant case. Where search warrants are involved, there can be no doubt

that the only “process that is due” is supplied by the Fourth Amendment. Gerstein,

420 U.S. at 125 n.27 (internal quotation marks omitted).

In my view, the majority’s willingness to entertain the applicability of

Mathews to search-warrant applications is unjustified – and profoundly unwise.

Both this Court and the Supreme Court have counseled against importing the

Mathews scheme into the procedural framework enshrined in the Bill of Rights.

Indeed, because the “Bill of Rights speaks in explicit terms to many aspects of

criminal procedure,” the “expansion of those constitutional guarantees under the

open-ended rubric of the Due Process Clause invites interference with . . . the

careful balance that the Constitution strikes between liberty and order.” Medina v.

California, 505 U.S. at 443; see also id. (“[I]t has never been thought that decisions

under the Due Process Clause establish this Court as a rule-making organ for the

promulgation of . . . rules of criminal procedure.” (alteration adopted and internal

quotation marks omitted)); Hines v. Miller, 318 F.3d 157, 161 (2d Cir. 2003) (“We

agree . . . that it is inappropriate to employ the Mathews balancing test in criminal

cases.”). The danger is clear: more process does not sharpen the Constitution’s

vision for criminal justice, liberty, and order; it risks distorting that vision.

Unlike the majority, then, I would use this opportunity to halt Mathews’s

slow drift into criminal proceedings and instead rely on the “careful balance” that

the Fourth Amendment strikes between “liberty and order.” Medina, 505 U.S. at

443. Based on that authority, and that authority alone, I would uphold the ex parte

search-warrant applications involved here as constitutional under the Warrants

Clause. See U.S. Const. amend. IV. Because those warrants were undoubtedly

based “upon probable cause, [were] supported by Oath or Affirmation, and

particularly describ[ed] the place to be searched, and the person or things to be

seized,” id., the requirements of the Fourth Amendment were clearly met. And

those requirements – not Mathews – are all that matter here, since “[t]he Fourth

Amendment was tailored explicitly for the criminal justice system, and its balance

between individual and public interests always has been thought to define the

‘process that is due’ for seizures of person or property in criminal cases.” Gerstein,

420 U.S. at 125 n.27.

United States v. Leeper

Authorities cited

Opinion · public domain