Roxana Santos v. Frederick County Board of Commissioners, 725 F.3d 451

Santos, a Salvadoran native, worked in Frederick, Maryland, and was questioned by Frederick County deputies while on a public sidewalk outside her workplace in 2008.
The deputies, not authorized under the Sheriff’s 1357(g) agreement to enforce immigration law, approached Santos during a routine patrol.
After Santos produced a national ID, the deputies conducted a warrant check and learned of an outstanding ICE removal warrant for her deportation.
Deputies gestured for Santos to remain seated before confirming the ICE warrant was active, at which point they seized and later arrested her.
The district court granted summary judgment to deputies and the Sheriff, dismissed the 1983 claims against the municipal defendants, and stayed/denied others; Santos appealed.
The Fourth Circuit held that the seizure occurred when the gesture to remain seated was made, and that civil ICE warrants do not justify detention/arrest absent federal authorization; however, individual officers have qualified immunity, while municipal defendants do not; remanded to address Monell liability issues.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Santos was seized at the initial approach	Santos argues seizure occurred when deputies surrounded and questioned her.	Defendants contend seizure occurred only after obtaining warrant information.	Seizure did not occur at initial approach; it occurred when Openshaw gestured to remain seated.
Whether detention/arrest based on a civil ICE warrant violated the Fourth Amendment	Detention/arrest based solely on a civil immigration warrant was unlawful.	Argues statutory authority under 1357(g) and related provisions allowed detention/arrest.	Detention/arrest based solely on a civil ICE warrant violated the Fourth Amendment; authority lacking unless federally directed/authorized.
Whether the deputies were entitled to qualified immunity	The right not to be seized/arrested solely on civil immigration violations was clearly established.	No clearly established law at the time forbade the seizure.	Right was not clearly established at the time; Deputies entitled to qualified immunity for individual claims.
Whether Monell official-capacity/municipal liability lies	Municipal defendants can be liable for unconstitutional acts of deputies under Monell.	Qualified immunity shields individuals; district court erred by dismissing municipal claims.	Because deputies violated the Fourth Amendment, qualified immunity does not bar municipal claims; remand to address policy/custom liability.

Florida v. Bostick, 501 U.S. 429 (1991) (police questioning can be non-seizure in public settings)
Mendenhall, 446 U.S. 544 (1980) (categorizes police-citizen encounters; seizure depends on being not free to leave)
Terry v. Ohio, 392 U.S. 1 (1968) (reasonable suspicion needed for brief detentions)
Brendlin v. California, 551 U.S. 249 (2007) (seizure occurs when police show unambiguous restraint)
Arizona v. United States, 132 S. Ct. 2492 (2012) (limits on local enforcement of federal civil immigration laws; 1357(g) implications)