Fourth Amendment Seizure
What does "Fourth Amendment Seizure" mean in law?
A Fourth Amendment seizure of a person occurs when a reasonable person would not feel free to leave or to decline an officer's requests, as articulated in United States v. Mendenhall (1980). For property, a seizure occurs when there is a meaningful interference with an individual's possessory interest. The distinction between a consensual encounter (no seizure), an investigatory stop (brief seizure requiring reasonable suspicion under Terry v. Ohio), and a full arrest (seizure requiring probable cause) is critical because the level of justification the government needs escalates with the intrusiveness of the seizure.
Definition
A Fourth Amendment seizure of a person occurs when a reasonable person would not feel free to leave or to decline an officer's requests, as articulated in United States v. Mendenhall (1980). For property, a seizure occurs when there is a meaningful interference with an individual's possessory interest. The distinction between a consensual encounter (no seizure), an investigatory stop (brief seizure requiring reasonable suspicion under Terry v. Ohio), and a full arrest (seizure requiring probable cause) is critical because the level of justification the government needs escalates with the intrusiveness of the seizure.
Example
When four officers surrounded a bus passenger, blocked the aisle, and demanded to search his bag, the court found this was a seizure because a reasonable person in that situation would not have felt free to terminate the encounter and leave.