Case Law

Terry v. Ohio (1968)

Established the “Terry stop” - officers can briefly detain and frisk someone based on reasonable suspicion (a lower standard than probable cause) that criminal activity is afoot and the person may be armed and dangerous. The frisk is limited to a pat-down for weapons.

Graham v. Connor (1989)

Set the standard for excessive force claims. Use of force must be “objectively reasonable” based on the totality of circumstances from the perspective of a reasonable officer on scene, not with 20/20 hindsight. Courts must consider the severity of the crime, immediate threat, and whether the suspect is resisting or fleeing.

Minnesota v. Dickerson (1993)

Extended Terry by establishing the “plain feel” doctrine - if during a lawful Terry frisk an officer feels something whose incriminating nature is immediately apparent, it can be seized. However, the officer cannot manipulate the object to determine what it is.

Florida v. J.L. (2000)

An anonymous tip alone, without corroboration or indicia of reliability, does not provide reasonable suspicion for a Terry stop. Officers need more than just an uncorroborated anonymous call to justify a stop and frisk.

Pennsylvania v. Mimms (1977)

Officers can order drivers (and passengers, per Maryland v. Wilson) out of vehicles during lawful traffic stops without additional justification. This is considered a minimal intrusion justified by officer safety concerns.

Garrity v. New Jersey (1967)

Statements obtained from officers under threat of termination during internal investigations cannot be used against them in criminal proceedings. Officers cannot be forced to choose between self-incrimination and losing their jobs.

Chimel v. California (1969)

Defines the scope of warrantless searches incident to arrest - officers can search the arrestee’s person and the area within their immediate control (grab area/wingspan) to prevent destruction of evidence and ensure officer safety.

Illinois v. Wardlow (2000)

Unprovoked flight upon seeing police in a high-crime area contributes to reasonable suspicion justifying a Terry stop, though it’s not automatically sufficient by itself. It’s one factor officers can consider.

Florida v. Bostick (1991)

Police-citizen encounters on buses (and similar confined spaces) aren’t automatically seizures. The test is whether a reasonable person would feel free to decline the officer’s requests or terminate the encounter.

Miranda v. Arizona (1966)

Established Miranda warnings - suspects in custody must be informed of their right to remain silent, that statements can be used against them, their right to an attorney, and right to appointed counsel if they can’t afford one, before custodial interrogation.

Mapp v. Ohio (1961)

Established the exclusionary rule at the state level - evidence obtained through illegal searches and seizures in violation of the Fourth Amendment cannot be used in state criminal prosecutions. This extended the federal exclusionary rule to all states, making illegally obtained evidence inadmissible in court.

Tennessee v. Garner (1985)

Restricts use of deadly force against fleeing suspects. Officers cannot use deadly force to prevent escape unless the suspect poses a significant threat of death or serious physical injury to officers or others. The old “fleeing felon” rule allowing shooting any fleeing felon was deemed unconstitutional.

Hiibel v. Sixth Judicial District Court of Nevada (2004)

States can require suspects to identify themselves during a lawful Terry stop. Refusing to provide identification when state law requires it during a valid stop does not violate the Fourth or Fifth Amendments. Officers can arrest for failure to identify in “stop and identify” states.

Arizona v. Gant (2009)

Narrowed vehicle searches incident to arrest. Officers can search a vehicle after arrest only if: (1) the arrestee is within reaching distance of the passenger compartment at the time of search, or (2) it’s reasonable to believe the vehicle contains evidence of the offense of arrest. This limited the broad Belton rule.

Brady v. Maryland (1963)

Prosecutors must disclose material exculpatory evidence to the defense. Suppression of evidence favorable to the accused violates due process when the evidence is material to guilt or punishment. This creates an ongoing obligation for prosecutors to share evidence that could help the defense.

Giglio v. United States (1972)

Extended Brady to include impeachment evidence - prosecutors must disclose any deals, promises, or inducements made to witnesses, including agreements for leniency. Failure to disclose that a key witness received benefits in exchange for testimony violates due process and can overturn convictions.

Carroll v. United States (1925)

Established the automobile exception: vehicles can be searched without a warrant if there’s probable cause, due to their mobility.

United States v. Ross (1982)

If probable cause exists to search a vehicle, officers can search any container within it that might hold the suspected evidence.

California v. Acevedo (1991)

Officers with probable cause to search a container in a vehicle can search it without a warrant, even if they lack probable cause to search the entire vehicle.

Schneckloth v. Bustamonte (1973)

Established standards for voluntary consent searches; consent must be freely given but police don’t need to inform people they can refuse.

Illinois v. Rodriguez (1990)

Third-party consent is valid if officers reasonably believe the person has authority over the premises, even if they actually don’t.

United States v. Mendenhall (1980)

Defined when a “seizure” occurs: when a reasonable person wouldn’t feel free to leave or terminate the encounter.

Whren v. United States (1996)

Any traffic violation, no matter how minor, gives officers legal justification to stop a vehicle; the officer’s subjective motivations don’t matter.

Atwater v. City of Lago Vista (2001)

Officers can make custodial arrests for minor offenses, even fine-only misdemeanors.

Rhode Island v. Innis (1980)

“Interrogation” under Miranda includes not just direct questioning but also any police words or actions reasonably likely to elicit an incriminating response.

Berghuis v. Thompkins (2010)

Suspects must unambiguously invoke Miranda rights; silence alone isn’t enough. Once rights are waived, voluntary statements are admissible.

Maryland v. Shatzer (2010)

After a suspect invokes their right to counsel, a break in custody of 14+ days allows police to re-approach without counsel present.

Davis v. United States (1994)

Ambiguous or equivocal requests for counsel don’t require officers to stop questioning; the request must be clear and unequivocal.

United States v. Wade (1967)

Defendants have a right to counsel at post-indictment lineups.

Neil v. Biggers (1972)

Established factors for evaluating eyewitness identification reliability.

Horton v. California (1990)

Officers can seize evidence in plain view even if the discovery wasn’t inadvertent, as long as they’re lawfully present and the incriminating nature is immediately apparent.

Maryland v. Buie (1990)

Officers can conduct protective sweeps of areas immediately adjoining an arrest location, and can look in other areas if they have reasonable suspicion someone dangerous is present.

Kentucky v. King (2011)

Police don’t create exigent circumstances merely by knocking on a door (unless they violate the Fourth Amendment in doing so).

South Dakota v. Opperman (1976)

Routine inventory searches of impounded vehicles are constitutional if conducted according to standardized procedures.

Katz v. United States (1967)

Fourth Amendment protects people’s reasonable expectations of privacy, not just property. Established the “reasonable expectation of privacy” test.

Kyllo v. United States (2001)

Using thermal imaging devices to detect heat from a home constitutes a search requiring a warrant.

Riley v. California (2014)

Officers generally need a warrant to search cell phones incident to arrest, even though the phone was on the arrestee’s person.

Harlow v. Fitzgerald (1982)

Established qualified immunity standard: officers are immune from civil liability unless they violated clearly established constitutional rights that a reasonable officer would have known about.