Seizure

What It Is

A “seizure” under the Fourth Amendment happens when the government meaningfully restricts your freedom of movement. This can range from a brief Terry stop on the sidewalk to a full custodial arrest. The concept matters because the Fourth Amendment only protects you from unreasonable seizures — so the first question is always: were you seized at all?

The Legal Test

The Supreme Court established the standard in United States v. Mendenhall, 446 U.S. 544 (1980): a seizure occurs when, considering all the circumstances, a reasonable person would not feel free to leave or to decline the officer’s requests.

Factors that indicate a seizure include:

• Physical touching by the officer
• Display of a weapon
• Commands or authoritative tone (“Stop!” “Don’t move!”)
• Blocking your path with a vehicle or body
• Retaining your documents (ID, license, passport)
• Multiple officers surrounding you

A friendly conversation where you’re free to walk away is not a seizure. But the moment an officer uses authority to make you stay, it likely becomes one.

Physical Force as Seizure

In Torres v. Madrid, 592 U.S. 306 (2021), the Supreme Court held that shooting someone is a seizure — even if the person escapes and isn’t actually stopped. The application of physical force with intent to restrain is enough, regardless of whether it succeeds.

This is important for excessive force claims: you don’t need to prove the officer successfully detained you to argue the Fourth Amendment applies.

Types of Seizures

Seizures exist on a spectrum:

• Consensual encounter — Not a seizure. You’re free to leave. No Fourth Amendment protections apply.
• Investigatory stop (Terry stop) — Brief seizure requiring reasonable suspicion. Limited in scope and duration.
• De facto arrest — A stop that becomes so prolonged or intrusive it crosses into an arrest, requiring probable cause.
• Formal arrest — Full custodial seizure requiring probable cause.

Why It Matters in § 1983 Cases

Before you can bring a Fourth Amendment claim — whether for false arrest, excessive force, or unlawful detention — you generally need to show that a seizure occurred. If the government argues you were “free to leave,” they’re trying to avoid Fourth Amendment scrutiny entirely.

Key questions to ask:

• Would a reasonable person have felt free to leave?
• Did the officer use physical force or a show of authority?
• How long were you detained, and under what conditions?

Key Cases

• Terry v. Ohio, 392 U.S. 1 (1968) — Established that brief investigatory stops are seizures requiring reasonable suspicion
• United States v. Mendenhall, 446 U.S. 544 (1980) — “Free to leave” test for seizures
• Torres v. Madrid, 592 U.S. 306 (2021) — Physical force with intent to restrain is a seizure even if unsuccessful
• California v. Hodari D., 499 U.S. 621 (1991) — For show-of-authority seizures, submission is required