Stops Seizures1995132 L. Ed. 2d 564
Vernonia School District 47J v. Acton is important for police officers because it shows that not every Fourth Amendment search requires individualized suspicion, but it also shows that suspicionless searches are allowed only in limited settings. The Court’s reasoning depended heavily on the school environment, the special role of school officials, the voluntary nature of athletic participation, the reduced privacy expectations of student athletes, and the fact that the program was not designed as a criminal evidence-gathering tool.
Stops Seizures2002153 L. Ed. 2d 242
United States v. Drayton is an important case for consent encounters, especially transportation interdiction work. Officers may approach people in public settings, including passengers on a bus, ask questions, request identification, and ask for consent to search, as long as the encounter remains voluntary under the totality of the circumstances.
Stops Seizures1997137 L. Ed. 2d 615
Richards v. Wisconsin is an important reminder that no-knock entry decisions must be based on facts, not labels. A search warrant involving drugs does not automatically justify skipping knock-and-announce.
Stops Seizures198583 L. Ed. 2d 604
United States v. Hensley is important for patrol officers because it confirms that officers may act on wanted flyers, BOLOs, and similar interagency notices. An officer in the field does not have to stop and independently re-investigate the entire case before making a brief stop.
Stops Seizures198794 L. Ed. 2d 347
Arizona v. Hicks is an important reminder that being lawfully present at a scene does not give officers unlimited authority to examine everything in the area. If officers enter a home because of an emergency, a protective sweep, a warrant, or another lawful reason, they may see things in plain view.
Stops Seizures1989104 L. Ed. 2d 1
For officers, United States v. Sokolow reinforces that reasonable suspicion is a common-sense, total-picture standard. Officers should document the specific facts they knew before the stop and explain how those facts connected to suspected criminal activity.
Stops Seizures1990108 L. Ed. 2d 276
Maryland v. Buie gives officers a safety tool during in-home arrests, but it also places clear limits on that tool. When making an arrest inside a residence, officers may check immediately adjoining areas where another person could quickly launch an attack.
Stops Seizures1998142 L. Ed. 2d 492
Knowles v. Iowa is an important limitation on traffic-stop searches. If an officer stops a driver for a traffic offense and decides to issue a citation rather than make a custodial arrest, the officer does not get automatic authority to search the vehicle as a search incident to arrest.
Stops Seizures2021593 U.S. 345
For tribal police officers, United States v. Cooley confirms that they may take reasonable enforcement action when they encounter a non-Indian on a public right-of-way within the reservation and have grounds to suspect a state or federal crime. The officer may investigate, address immediate safety concerns, and temporarily detain the person while contacting state or federal officers.
Stops Seizures1990110 L. Ed. 2d 301
Alabama v. White gives officers a usable but limited rule for anonymous tips. If an anonymous caller reports criminal activity, officers should not assume the tip alone is enough for a stop.
Stops Seizures2005160 L. Ed. 2d 842
Illinois v. Caballes is important for officers because it permits a drug-detection dog sniff during a valid traffic stop without requiring separate reasonable suspicion of drug activity. If the driver is lawfully stopped for a traffic violation, and a K-9 team is present or arrives while the stop is still being handled, the exterior sniff itself does not automatically create a Fourth Amendment problem.
Stops Seizures2006165 L. Ed. 2d 56
Hudson v. Michigan does not mean officers can ignore the knock-and-announce rule. The rule remains part of Fourth Amendment law, unless a recognized exception applies, such as reasonable suspicion that announcing would create danger, allow evidence to be destroyed, or be futile.
Stops Seizures1998140 L. Ed. 2d 191
United States v. Ramirez is important for warrant service and forced-entry planning. The case confirms that the key Fourth Amendment question is reasonableness under the circumstances, not whether the entry caused some property damage.
Stops Seizures2001148 L. Ed. 2d 838
Illinois v. McArthur supports a careful, warrant-focused approach when officers have probable cause but do not yet have a search warrant. If officers reasonably believe evidence is inside a residence and that a person will destroy it if allowed inside alone, they may be able to hold the scene long enough to get a warrant without conducting a warrantless search.
Stops Seizures2011179 L. Ed. 2d 1149
Ashcroft v. al-Kidd is not a general permission slip to use material witness warrants as a substitute for criminal probable cause. Officers should not read the case as saying that a material witness warrant can be obtained whenever investigators want to detain a person but lack evidence to arrest for a crime.
Stops Seizures198375 L. Ed. 2d 903
Kolender v. Lawson is mainly a vagueness case, but it has important street-level consequences. Officers need to understand the difference between asking for identification and enforcing a criminal statute that requires identification.
Stops Seizures2000529 U.S. 266
Florida v. J. L.: florida v. <dot> <dot> is a key case for patrol officers responding to anonymous weapons calls. If the only information is an anonymous tip that a person at a location, wearing certain clothing, has a gun, officers should understand that matching the description alone may not be enough for a lawful Terry frisk.
Stops Seizures1996134 L. Ed. 2d 911
Ornelas v. United States is important for police work because it shows that reasonable suspicion and probable cause must be built on clearly described facts, not just conclusions. An officer’s experience matters, but the report and testimony must explain what the officer observed and why those observations mattered.
Stops Seizures2007168 L. Ed. 2d 132
Brendlin v. California: for officers, the main lesson is straightforward: when you stop a car, you are stopping the passengers too. A passenger may later challenge the legality of the stop and seek suppression of evidence that flows from it.
Stops Seizures2003157 L. Ed. 2d 343
United States v. Banks is important for warrant service because it explains that knock-and-announce reasonableness is judged by real-world circumstances, not by a fixed stopwatch rule. Officers should still knock and announce when the Fourth Amendment requires it, but the amount of time they must wait before forced entry depends on what they are searching for, the risks present, and what happens at the door.
Stops Seizures2005161 L. Ed. 2d 299
For officers, Muehler v. Mena confirms that a search warrant carries with it limited authority to control the scene by detaining occupants while the warrant is executed. If officers are lawfully inside executing the warrant, they generally do not have to let occupants move freely through the residence or leave the scene while the search is underway.
Stops Seizures2013185 L. Ed. 2d 19
For officers serving search warrants, Bailey v. United States means that Summers detention authority has a geographic limit. If a person is on the premises or in the immediate area when the warrant is executed, officers may generally detain that person while the search is conducted.
Stops Seizures2006165 L. Ed. 2d 250
Samson v. California gives officers important authority when dealing with parolees, but it is not a blanket rule for every person or every supervision status. The decision applies to parolees who are subject to a valid search condition that allows searches without a warrant and without cause.
Stops Seizures2004159 L. Ed. 2d 292
Hiibel v. Sixth Judicial Dist. Court of Nev., Humboldt Cty.: for officers, Hiibel is important but limited. It does not create a general federal power to demand identification from anyone at any time.
Stops Seizures2000145 L. Ed. 2d 570
For officers, Illinois v. Wardlow supports a stop when there is more than mere presence in a high-crime area. The key facts were Wardlow’s location in an area known for narcotics trafficking and his unprovoked flight as soon as he saw police.
Stops Seizures2002151 L. Ed. 2d 740
United States v. Arvizu is an important reasonable-suspicion case for officers conducting investigative stops. The practical lesson is that courts should look at the whole picture, not isolate each factor.
Stops Seizures2009174 L. Ed. 2d 354
For police officers, Safford Unified School District 1 v. Redding is a reminder that the Fourth Amendment focuses heavily on the degree of intrusion. A search that may begin lawfully can become unconstitutional if it becomes too invasive without specific facts supporting that level of intrusion.
Stops Seizures2009172 L. Ed. 2d 694
Arizona v. Johnson is important because it separates two issues that officers must keep straight during traffic stops: the legality of the stop and the legality of the frisk. If the vehicle stop is lawful, the occupants are lawfully detained while the stop is being handled.
Stops Seizures2012183 L. Ed. 2d 351
For officers, Arizona v. United States is an important reminder that immigration status can be relevant during a lawful police encounter, but it does not automatically create state arrest authority. If an officer has lawfully stopped or arrested someone for a valid reason, the officer may be able to contact federal immigration authorities or make a reasonable status inquiry consistent with agency policy and state law.
Stops Seizures2016579 U.S. 232
Utah v. Strieff does not give officers permission to stop people without reasonable suspicion. The initial stop in the case was treated as unlawful, and the Court’s ruling depended heavily on the later discovery of a valid, pre-existing warrant and the absence of purposeful or flagrant misconduct.
Stops Seizures2012182 L. Ed. 2d 566
Florence v. Board of Chosen Freeholders of County of Burlington: for patrol officers, the main lesson is that the constitutional analysis changes once a person is lawfully arrested and brought into a jail for admission to the general population. The Supreme Court gave substantial deference to correctional officials’ need to keep contraband, weapons, and other risks out of the jail environment.
Stops Seizures2014188 L. Ed. 2d 680
For officers, Prado Navarette v. California supports stopping a vehicle based on a 911 report when the caller gives specific information, appears to be reporting firsthand and recent events, and describes dangerous driving that may suggest impairment or an immediate threat to public safety. Officers do not always need to personally observe a new traffic violation before stopping the vehicle, if the tip itself provides reasonable suspicion.
Stops Seizures2015575 U.S. 348
For officers, Rodriguez v. United States means the clock matters, but the reason for the time matters even more. During a traffic stop, officers may take the time reasonably needed to address the traffic violation, run normal records checks, verify documents, and take legitimate safety precautions.
Stops Seizures2020589 U.S. 376
For patrol officers, Kansas v. Glover supports a traffic stop when a records check shows that the vehicle’s registered owner has a revoked license and there is no information suggesting the owner is not behind the wheel. The officer does not have to first observe a separate traffic violation, and the officer does not have to positively identify the driver before the stop, as long as the stop is based on reasonable suspicion under the circumstances.
Stops Seizures1990110 L. Ed. 2d 412
For police officers, Michigan Department of State Police v. Sitz means that DUI checkpoints are not automatically unconstitutional just because officers lack individualized suspicion for each driver stopped. A checkpoint may be lawful if it is structured, limited, and aimed at roadway safety rather than general crime control.