An officer who accompanied an arrestee to the arrestee’s residence to obtain identification properly seized contraband in plain view. Washington v. Chrisman, 455 U.S. 1, 102 S. Ct. 812, 70 L. Ed. 2d 778 (1982).

Officers who have legitimately stopped an automobile and who have probable cause to believe contraband is concealed somewhere within it may conduct a warrantless search of the vehicle as thorough as could be authorized by warrant. United States v. Ross, 456 U.S. 798, 102 S. Ct. 2157, 72 L. Ed. 2d 572 (1982).

When an officer, after stopping a defendant’s car at a routine driver’s license checkpoint, saw a tied-off party balloon in plain sight, the officer had probable cause to believe the balloon contained an illicit substance. Hence, a warrantless seizure of the balloon was legal. Texas v. Brown, 460 U.S. 730, 103 S. Ct. 1535, 75 L. Ed. 2d 502 (1983).

A warrantless search by arson investigators of the defendant’s fire-damaged home that was not a continuation of an earlier search was unconstitutional. Michigan v. Clifford, 464 U.S. 287, 104 S. Ct. 641, 78 L. Ed. 2d 477 (1984).

When a damaged shipping package was examined by company employees who discovered white powder, a subsequent warrantless field test by police was constitutional. United States v. Jacobsen, 466 U.S. 109, 104 S. Ct. 1652, 80 L. Ed. 2d 85 (1984).

Discussing the “open fields” doctrine. Oliver v. United States, 466 U.S. 170, 104 S. Ct. 1735, 80 L. Ed. 2d 214 (1984).

The warrantless, nighttime entry of the defendant’s home for arrest for a civil, nonjailable traffic offense was not justified under the “hot pursuit” doctrine or the preservation of evidence doctrine. Welsh v. Wisconsin, 466 U.S. 740, 104 S. Ct. 2091, 80 L. Ed. 2d 732 (1984).

School officials need not obtain a warrant before searching a student. The legality of the search depends on the reasonableness, under all circumstances, of the search. New Jersey v. T.L.O., 469 U.S. 325, 105 S. Ct. 733, 83 L. Ed. 2d 720 (1985).

When officers were entitled to seize packages in a vehicle and could have searched them immediately without a warrant, a warrantless search of the packages three days later was reasonable. United States v. Johns, 469 U.S. 478, 105 S. Ct. 881, 83 L. Ed. 2d 890 (1985).

The vehicle exception for warrantless searches applies to motor homes. California v. Carney, 471 U.S. 386, 105 S. Ct. 2066, 85 L. Ed. 2d 406 (1985).

The good faith exception to the exclusionary rule applies when an officer reasonably relies upon a statute allowing a warrantless administrative search that was subsequently ruled unconstitutional. Illinois v. Krull, 480 U.S. 340, 107 S. Ct. 1160, 94 L. Ed. 2d 364 (1987).

A protective sweep of a residence in conjunction with an arrest is permissible if police reasonably believe that the area harbors an individual posing a danger to officers or others. Maryland v. Buie, 494 U.S. 325, 110 S. Ct. 1093, 108 L. Ed. 2d 276 (1990).

Inadvertence is not a necessary condition to a “plain view” seizure. Horton v. California, 496 U.S. 128, 110 S. Ct. 2301, 110 L. Ed. 2d 112 (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).

A determination of probable cause made within 48 hours of a warrantless arrest generally meets the promptness requirement. If a hearing is held more than 48 hours following the arrest, the burden shifts to the government to demonstrate an emergency or extraordinary circumstances. County of Riverside v. McLaughlin, 500 U.S. 44, 111 S. Ct. 1661, 114 L. Ed. 2d 49 (1991).

There shall be one rule governing all automobile searches. The police may search the car and all containers within it without a warrant when they have probable cause to believe contraband or evidence is contained in either. California v. Acevedo, 500 U.S. 565, 111 S. Ct. 1982, 114 L. Ed. 2d 619 (1991).

If during a lawful weapons pat down an officer feels an object whose contours or mass makes its identity immediately apparent, there has been no invasion of privacy beyond that already authorized. Minnesota v. Dickerson, 508 U.S. 366, 113 S. Ct. 2130, 124 L. Ed. 2d 334 (1993).

An officer making a traffic stop may order passengers to get out of the vehicle pending the completion of the stop. Maryland v. Wilson, 519 U.S. 408, 117 S. Ct. 882, 137 L. Ed. 2d 41 (1997).

Persons observed through a window in a home where they were not overnight guests but were present for a short period to engage in a primarily commercial illegal drug transaction, had no expectation of privacy in the home and the observation of those persons was not a constitutionally prohibited search. Minnesota v. Carter, 525 U.S. 83, 119 S. Ct. 469, 142 L. Ed. 2d 373 (1998).

The issuance of a traffic citation without an arrest did not authorize a full search of the vehicle. Knowles v. Iowa, 525 U.S. 113, 119 S. Ct. 484, 142 L. Ed. 2d 492 (1998).

When there is probable cause to search a vehicle for contraband, officers may examine containers in the vehicle without a showing of individualized probable cause for each container. The container may be searched whether or not its owner is present as a passenger, or otherwise, because it may contain contraband that the officers reasonably believe is in the car. Wyoming v. Houghton, 526 U.S. 295, 119 S. Ct. 1297, 143 L. Ed. 2d 408 (1999).

Police need not obtain a warrant before seizing an automobile from a public place when there is probable cause to believe that the vehicle is forfeitable contraband. Florida v. White, 526 U.S. 559, 119 S. Ct. 1555, 143 L. Ed. 2d 748 (1999).

The exception to the requirement of a warrant for automobiles does not require a separate finding of exigency, in addition to a finding of probable cause. Maryland v. Dyson, 527 U.S. 465, 119 S. Ct. 2013, 144 L. Ed. 2d 442 (1999).

When there is probable cause to search a motor vehicle, the search is not unreasonable if the search is based on facts that would justify the issuance of a warrant, although a warrant was not obtained. No separate finding of exigent circumstances is required. Maryland v. Dyson, 527 U.S. 465, 119 S. Ct. 2013, 144 L. Ed. 2d 442 (1999).

There is no murder scene exception to the warrant requirement. Flippo v. West Virginia, 528 U.S. 11, 120 S. Ct. 7, 145 L. Ed. 2d 16 (1999).

Nervous, evasive behavior is a pertinent factor in determining reasonable suspicion. Headlong flight is the consummate act of evasion. Illinois v. Wardlow, 528 U.S. 119, 120 S. Ct. 673, 145 L. Ed. 2d 570 (2000).

An anonymous tip that a person is carrying a gun, without more, is insufficient to justify a police officer’s stop and frisk of a person. The tip must bear indicia of reliability. Reasonable suspicion requires that a tip be reliable in its assertion of criminal activity, not just in its tendency to identify a person. Florida v. J.L., 529 U.S. 266, 120 S. Ct. 1375, 146 L. Ed. 2d 254 (2000).

Stopping vehicles at highway checkpoints without any individualized suspicion to interdict illegal drugs was an unreasonable seizure under the 4th amendment because the primary purpose was to uncover evidence of ordinary criminal wrongdoing, unlike checkpoints to check for drunk driving or illegal immigrants. City of Indianapolis v. Edmond, 531 U.S. 32, 121 S. Ct. 447, 148 L. Ed. 2d 333 (2000).

The police acted reasonably when, with probable cause to believe that the defendant had hidden drugs in his home, they prevented the man from entering the home for about two hours until a search warrant could be obtained. Illinois v. McArthur, 531 U.S. 326, 121 S. Ct. 946, 148 L. Ed. 2d 838 (2001).