PER CURIAM.
Charles Edward Senter appeals the summary judgment dismissal of his 42 U.S.C. § 1983 complaint. Senter was stopped by police at approximately 12:30 a.m. on January 3, 1999, for traffic violations. He was arrested and was detained until 5:30 p.m. when a judge granted release on bail. Senter subsequently was found guilty of failing to signal continuously for the last 100 feet of movement prior to turning, operating a motor vehicle without holding a driver’s license, and failing to establish financial responsibility.
Our review of the dismissal of Senter’s complaint on summary judgment is de novo. Mace v. City of Palestine, 333 F.3d 621, 623 (5th Cir.2003). “ ‘Summary judgment is proper when, viewing the evidence in the light most favorable to the nonmovant, there is no genuine issue of material fact precluding judgment as a matter of law in favor of the movant.’ ” Mace, 333 F.3d at 623. To defeat summary judgment, the nonmovant must set forth specific facts showing the existence of a genuine issue for trial. Fed. R. Civ. P. 56(e). The nonmovant cannot meet his burden with unsubstantiated assertions, conclusional allegations, or a scintilla of evidence. Little v. Liquid Air Corp., 37 F.3d 1069, 1075 (5th Cir.1994) (en banc).
Senter contends that Texas law authorized his release either with a citation or a bond and that due process required the defendants to explain why they did not release him on these terms. Senter contends that the City of Dalworthington Gardens is hable based on its oppressive custom and pohcy of detaining persons after probable cause to detain them on a warrantless arrest is no longer present.
Senter does not argue that Texas law required his release on a citation or bond. He does not argue that Texas law prohibited his arrest and detention. Senter does not provide support for his position that due process required an explanation for the detention. Senter has not demonstrated the violation of a constitutional right on his claims concerning his detention. See County of Riverside v. McLaughlin, 500 U.S. 44, 52-56, 111 S.Ct. 1661, 114 L.Ed.2d 49 (1991). The failure to estabhsh a constitutional violation defeats Senter’s claims of municipal liability arising from the detention. Olabisiomotosho v. City of Houston, 185 F.3d 521, 529 (5th Cir.1999).
Senter contends that the City of Dalworthington Gardens is hable based on its oppressive custom and pohcy of setting bail in the amount of double the fine for the offense. To estabhsh municipal liability under 42 U.S.C. § 1983, a plaintiff must show that a pohcy or custom caused the constitutional violation. Richardson v. Oldham County, 12 F.3d 1373, 1381 (5th Cir.1994). As the district court concluded, the action that a judge takes pursuant to judicial duty cannot constitute municipal policy. Johnson v. Moore, 958 F.2d 92, 94 (5th Cir.1992). Senter has not attempted to refute the district court’s reasoning, and thus, he has effectively abandoned any appeal of this issue. See Brinkmann v. Dallas County Deputy Sheriff Abner, 813 F.2d 744, 748 (5th Cir.1987).
Senter concedes that his claims against Judge Hudson were barred by judicial immunity. Hudson has not addressed the district court’s dismissal pursuant to Heck v. Humphrey, 512 U.S. 477, 486, 114 S.Ct. 2364, 129 L.Ed.2d 383 (1994), of his claims concerning the stop and arrest, and he has not asserted claims concerning the conditions of his confinement. Accordingly, Senter has abandoned these issues. Brinkmann, 813 F.2d at 748. The judgment of the district court is AFFIRMED.
Pursuant to 5th Cir. R. 47.5, the court has determined that this opinion should not be published and is not precedent except under the limited circumstances set forth in 5th Cir. R. 47.5.4.