The detention and interrogation of an airline passenger fitting a “drug courier profile” was unconstitutional. Florida v. Royer, 460 U.S. 491, 103 S. Ct. 1319, 75 L. Ed. 2d 229 (1983).

Under the “independent source” doctrine, evidence discovered during a valid search was admissible regardless of whether initial entry was illegal. Segura v. United States, 468 U.S. 796, 104 S. Ct. 3380, 82 L. Ed. 2d 599 (1984).

The “good faith” exception to the exclusionary rule allowed the admission of evidence obtained by officers acting in objectively reasonable reliance on a search warrant, issued by a detached and neutral magistrate, later found to be unsupported by probable cause. United States v. Leon, 468 U.S. 897, 104 S. Ct. 3405, 82 L. Ed. 2d 677 (1984).

Discussing the “good faith” exception to the exclusionary rule. Massachusetts v. Sheppard, 468 U.S. 981, 104 S. Ct. 3424, 82 L. Ed. 2d 737 (1984).

If a “wanted flyer” has been issued on the basis of articulable facts supporting reasonable suspicion that a wanted person has committed a crime, other officers may rely on the flyer to stop and question that person. United States v. Hensley, 469 U.S. 221, 105 S. Ct. 675, 83 L. Ed. 2d 604 (1985).

In assessing whether detention is too long to be justified as an investigative stop, it is appropriate to examine whether the police diligently pursued a means of investigation likely to quickly confirm or dispel their suspicions. United States v. Sharpe, 470 U.S. 675, 105 S. Ct. 1568, 84 L. Ed. 2d 605 (1985).

Proposed surgery under general anesthetic to recover a bullet from an accused robber’s body was an unreasonable search. Winston v. Lee, 470 U.S. 753, 105 S. Ct. 1611, 84 L. Ed. 2d 662 (1985).

Fingerprints were not admissible when the police transported the suspect to a station house for fingerprinting without consent, probable cause, or prior judicial authorization. Hayes v. Florida, 470 U.S. 811, 105 S. Ct. 1643, 84 L. Ed. 2d 705 (1985).

Apprehension by the use of deadly force is a seizure subject to the reasonableness requirement. Tennessee v. Garner, 471 U.S. 1, 105 S. Ct. 1694, 85 L. Ed. 2d 1 (1985).

When an officer stopped a car for traffic violations and reached into the car to move papers obscuring the vehicle identification number, discovered evidence was admissible. New York v. Class, 475 U.S. 106, 106 S. Ct. 960, 89 L. Ed. 2d 81 (1986).

The reasonable expectation of privacy was not violated when police, acting on an anonymous tip, flew over the defendant’s enclosed backyard and observed marijuana plants. California v. Ciraolo, 476 U.S. 207, 106 S. Ct. 1809, 90 L. Ed. 2d 210 (1986).

Defendants have no reasonable privacy interest in trash left on a curb for pick-up. Therefore, a warrantless search is not prohibited under federal law. California v. Greenwood, 486 U.S. 35, 108 S. Ct. 1625, 100 L. Ed. 2d 30 (1988).

The use of a roadblock to halt a suspect’s automobile constituted a seizure. Brower v. County of Inyo, 489 U.S. 593, 109 S. Ct. 1378, 103 L. Ed. 2d 628 (1989).

The impeachment exception to the exclusionary rule does not extend to the use of illegally obtained evidence to impeach testimony of defense witnesses other than the defendant. James v. Illinois, 493 U.S. 307, 110 S. Ct. 648, 107 L. Ed. 2d 676 (1990).

For a seizure of a person to occur there must either be an application of force, however slight, or when force is absent, submission to an officer’s “show of authority.” California v. Hodari D., 499 U.S. 621, 111 S. Ct. 1547, 113 L. Ed. 2d 690 (1991).

When an officer has no articulable suspicion regarding a person, but requests that person to allow the search of his luggage, there is no seizure of the person if a reasonable person would feel free to decline the officer’s request or end the encounter. Florida v. Bostick, 501 U.S. 429, 111 S. Ct. 2382, 115 L. Ed. 2d 389 (1991).

Fourth-amendment protections against unreasonable searches and seizures extend to civil matters. The illegal eviction of a trailer home from a private park with deputy sheriffs present to prevent interference was an unconstitutional seizure of property. Soldal v. Cook County, 506 U.S. 56, 113 S. Ct. 538, 121 L. Ed. 2d 450 (1992).

Whether police must “knock and announce” prior to entering a residence in executing a warrant is part of the reasonableness inquiry under the 4th amendment. Wilson v. Arkansas, 514 U.S. 927, 115 S. Ct. 1914, 131 L. Ed. 2d 976 (1995).

Public school students are granted lesser privacy protections than adults, and student athletes even less. Mandatory drug testing of student athletes did not violate the constitutional protection against unreasonable searches and seizures. Vernonia School District 47J v. Acton, 515 U.S. 646, 115 S. Ct. 2386, 132 L. Ed. 2d 564 (1995).

It is a violation of the 4th amendment for police to bring members of the media or other third persons into a home during the execution of a warrant when the presence of the third persons in the home is not in aid of the execution of the warrant. Wilson v. Layne, 526 U.S. 603, 119 S. Ct. 1692, 143 L. Ed. 2d 818 (1999).

Inherent in the authorization under Summers, 452 U.S. 692 (1981), to detain an occupant of the place to be searched is the authority to use reasonable force to effectuate the detention. Use of force in the form of handcuffs to effectuate detention in the garage outside the house being searched was reasonable when the governmental interests outweighed the marginal intrusion. Muehler v. Mena, 544 U.S. 93, 125 S. Ct. 1465, 161 L. Ed. 2d 299 (2005).

Violation of the “knock-and-announce” rule does not require the suppression of all evidence found in the search. Hudson v. Michigan, 547 U.S. 586, 126 S. Ct. 2159, 165 L. Ed. 2d 56 (2006).

A claim of excessive force in the course of making a seizure of the person is properly analyzed under the 4th amendment’s objective reasonableness standard. A police officer’s attempt to terminate a dangerous high-speed car chase that threatens the lives of innocent bystanders does not violate the 4th amendment, even when it places the fleeing motorist at risk of serious injury or death. Scott v. Harris, 550 U.S. 372, 127 S. Ct. 1769, 167 L. Ed. 2d 686 (2007).

To trigger the exclusionary rule, police conduct must be sufficiently deliberate that exclusion can meaningfully deter the conduct, and sufficiently culpable that such deterrence is worth the price paid by the justice system. The exclusionary rule serves to deter deliberate, reckless, or grossly negligent conduct, or in some circumstances recurring or systemic negligence. When police mistakes are the result of negligence, such as here when a cancelled warrant was not removed from a database, rather than systemic error or reckless disregard of constitutional requirements, any marginal deterrence does not pay its way. Herring v. United States, 555 U.S. 135, 129 S. Ct. 695, 172 L. Ed. 2d 496 (2009).

When officers make an arrest supported by probable cause for a serious offense and bring the suspect to the station to be detained in custody, taking and analyzing a cheek swab of the arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the 4th amendment. In the context of a valid arrest supported by probable cause, the arrestee’s expectations of privacy were not offended by the minor intrusion of a brief swab of his cheeks for DNA. That same context of arrest gives rise to significant state interests in identifying respondent not only so that the proper name can be attached to his charges but also so that the criminal justice system can make informed decisions concerning pretrial custody. Upon these considerations, DNA identification of arrestees is a reasonable search that can be considered part of a routine booking procedure. Maryland v. King, 569 U.S. 435, 133 S. Ct. 1958, 186 L. Ed. 2d 1 (2013).

The objective reasonableness of a particular seizure under the 4th amendment requires a careful balancing of the nature and quality of the intrusion on the individual’s 4th amendment interests against the countervailing governmental interests at stake analyzed from the perspective of a reasonable officer on the scene, rather than with the 20/20 vision of hindsight. If police officers are justified in firing at a suspect in order to end a severe threat to public safety, the officers need not stop shooting until the threat has ended. Plumhoff v. Rickard, 572 U.S. 765, 134 S. Ct. 2012, 188 L. Ed. 2d 1056 (2014).

Facial challenges to statutes authorizing warrantless searches under the 4th amendment are not categorically barred or especially disfavored. A facial challenge is an attack on a statute itself as opposed to a particular application. While such challenges are the most difficult to mount successfully, the U.S. Supreme Court has never held that these claims cannot be brought under any otherwise enforceable provision of the U.S. Constitution. City of Los Angeles v. Patel, 576 U.S. 409, 135 S. Ct. 2443, 192 L. Ed. 2d 435 (2015).

Search regimes where no warrant is ever required may be reasonable when special needs make the warrant and probable cause requirement impracticable, and when the primary purpose of the searches is distinguishable from the general interest in crime control. The U.S. Supreme Court has referred to this kind of search as an administrative search. In order for an administrative search to be constitutional, the subject of the search must be afforded an opportunity to obtain precompliance review before a neutral decisionmaker. City of Los Angeles v. Patel, 576 U.S. 409, 135 S. Ct. 2443, 192 L. Ed. 2d 435 (2015).

When an officer carries out a seizure that is reasonable, taking into account all relevant circumstances, there is no valid excessive force claim. A different 4th amendment violation cannot transform a later, reasonable use of force into an unreasonable seizure. County of Los Angeles v. Mendez, 581 U.S. 420, 137 S. Ct. 1539, 198 L. Ed. 2d 52 (2017).