Investigatory Stops of Persons. (See Full Document for Citations)


A seizure occurs when a reasonable person would not feel (1) “free to leave” or (2) “free to decline the officers' requests or otherwise terminate the encounter.” This standard is objective--it relies on whether a reasonable person would believe they are not free to leave rather than the suspect's subjective beliefs. Investigatory stops--brief seizures by police officers that fall short of traditional arrests--are governed by the Fourth Amendment and are lawful when justified by an officer's reasonable suspicion that an individual is engaged in criminal activity. Reasonable suspicion, a lesser standard than probable cause, exists when an officer can “point to specific and articulable facts, which, taken together with rational inferences from those facts, reasonably warrant th[e] intrusion.” A factor contributing to reasonable suspicion cannot be discounted just because there is an innocent explanation for the factor. Inarticulable hunches or generalized suspicions are insufficient. In adopting this formulation, the Supreme Court in Terry v. Ohio emphasized the importance of balancing “the need to search [or seize] against the invasion which the search [or seizure] entails.”

To determine whether reasonable suspicion existed at the time of the encounter, courts use a “totality of the circumstances” test. Police may stop and question a person--on foot or in a vehicle--for a limited period of time when they reasonably suspect that the person is engaged in criminal activity. The requirements for performing an investigatory frisk are discussed later in this Section.

Generally, investigatory stops are valid only if the suspicion is objectively reasonable. An officer's subjective intentions are irrelevant to the constitutionality of an investigatory stop under the Fourth Amendment. The primary bases for reasonable suspicion are a police officer's personal observations. and the officer's knowledge obtained or imputed from others that a crime has been committed. Courts, reasoning that an experienced officer can infer criminal activity from conduct that may seem innocuous to a lay observer, afford considerable deference to the observations and conclusions of the police.

Isolated or minimal instances of innocent activity are insufficient to constitute reasonable suspicion, but several apparently innocent activities taken together may meet the required standard.

Reliable information from an informant may also create reasonable suspicion and justify an investigatory stop. Courts assess the reliability of an informant's tip on a sliding scale: greater corroboration is necessary to justify acting on a tip from an unknown informant or an informant of uncertain trustworthiness; less corroboration suffices if the information is from a known source or a source that has proven previously trustworthy.

The presence of a suspect in a high-crime neighborhood does not, standing alone, justify a seizure. Courts may use this factor, however, in assessing the totality of circumstances surrounding a seizure. For example, a suspect's unprovoked flight upon seeing the police can justify a seizure when it occurs in a high-crime neigh-borhood. Generalized suspicion of criminal activity based solely on race does not justify a seizure.

Police activities during an investigatory stop must be reasonably related to the circumstances that initially justified the stop. During a lawful investigatory stop, police may ask questions or request documents to establish a person's identity and to confirm or dispel suspicions of criminal activity. If reasonable suspicion does not exist, police may still order occupants out of a vehicle they have lawfully stopped. In addition to detentions that are justified in the absence of a warrant, a detention may be justified because a valid warrant to search for contraband founded on probable cause implicitly carries with it the limited authority to detain the occupants on or in the immediate vicinity of the premises while the search is conducted.

When the police hold a suspect beyond the amount of time necessary to effectuate the purpose of the stop, the seizure becomes an arrest and must be supported by probable cause. The Supreme Court has declined to establish a bright-line rule to determine when an investigatory stop becomes an arrest. Instead, whether an investigatory stop has become an arrest is decided on a case-by-case basis. In making such decisions, courts consider the diligence of police in resolving their reasonable suspicion as quickly as possible, the scope and nature of the restraints placed on an individual's liberty, and whether police transported the individual to another location. The mere existence of a less intrusive means of investigation does not make a detention unreasonable. When a detainee's own actions contribute to the duration of a stop, a longer detention may be reasonable.

Under Terry, a police officer who makes an investigatory stop may conduct a limited pat-down, or frisk, of a suspect's outer clothing if the officer has reasonable suspicion that the suspect is armed and dangerous. The frisk may be conducted only if the officer has a reasonable belief that the detainee poses a threat to the officer's safety or the safety of others. Its scope must be limited to a search for weapons and may not be used to search for evidence of criminal activity.

Investigatory Detentions of Property. Under the Fourth Amendment, seizures of property in which a person has a legitimate privacy interest are valid only when police reasonably suspect that the property contains evidence of criminal activity. Seizures of property that is abandoned, in plain view, or obtained by consent are valid because the Fourth Amendment does not protect voluntarily surrendered privacy interests. When evaluating the reasonableness of a seizure of property, courts consider the duration and intrusiveness of the seizure, including how quickly police conducted their investigation of the seized property and whether police moved the seized property to a different location after seizing it.

Although brief seizures of property are valid if based on reasonable suspicion, a subsequent search of seized property is generally valid only if executed pursuant to a warrant issued upon probable cause.