The likelihood that evidence will be destroyed is an exigent circumstance justifying the warrantless entry of a residence. The mere presence of contraband does not create exigent circumstances. State v. Kiekhefer, 212 Wis. 2d 460, 569 N.W.2d 316 (Ct. App. 1997).
Detaining a person at his home and transporting him about one mile to the scene of an accident in which he was involved was an investigative stop and not an arrest, moved the person within the vicinity of the the stop within the meaning of s. 968.24 and was a reasonable part of an ongoing accident investigation. State v. Quartana, 213 Wis. 2d 440, 570 N.W.2d 618 (Ct. App. 1997).
The warrantless search of the defendant's purse when it was being returned to her while still in custody was authorized where the search would have been authorized at the time of the arrest and where the return of the purse could have given the defendant access to a weapon or evidence. State v. Wade, 215 Wis. 2d 678, 573 N.W.2d 228 (Ct. App. 1998).
Where a third-party lacks actual common authority to consent to a search of a defendant's residence, the police may rely on the third-party's apparent authority, if that reliance is reasonable. There is no presumption of common authority to consent to a search and the police must make sufficient inquiry to establish apparent authority. State v. Kieffer, 217 Wis. 2d 531, 577 N.W.2d 352 (1998).
A warrantless entry may be justified where the police engage in a bona fide community caretaker activity, although the ultimate test is reasonableness. The relevant considerations are the degree of public interest and exigency of the situation, the circumstances surrounding the search, whether an automobile is involved and whether there are alternatives to entry. State v. Paterson, 220 Wis. 2d 526, 583 N.W.2d 190 (Ct. App. 1998).
Reasonable suspicion required in a Terry investigative search is a common sense test of what under the circumstances a reasonable police officer would reasonably suspect in light of his or her experience. Police in an area known for drug dealing were justified to stop a driver when at nearly the same time they observed a woman approach then turn from the driver's parked car when she seemed to notice the police and the driver immediately exited the parking lot he was in. State v. Amos, 220 Wis. 2d 793, 584 N.W.2d 170 (Ct. App. 1998).
There is an expectation of privacy in commercial property that is applicable to administrative inspections. Because administrative inspections are not supported by probable cause, they will not be reasonable if, instead of being conducted to enforce a regulatory scheme, they are conducted as a pretext to obtain evidence of criminal activity. State v. Mendoza, 220 Wis. 2d 803, 584 N.W.2d 174 (Ct. App. 1998). Reversed on other grounds. State v. Mendoza, 227 Wis. 2d 838, 596 N.W.2d 736 (Ct. App. 1998).
There is no reasonable expectation of privacy in a hospital emergency or operating room. An officer who was present, with the consent of hospital staff, in an operating room during an operation and collected, as evidence, cocaine removed from an unconscious defendant's intestine did not conduct a search and did not make an unreasonable search. State v. Thompson, 222 Wis. 2d 179, 585 N.W.2d 905 (Ct. App. 1998).
A warrant authorizing the search of a particularly described premises may permit the search of vehicles owned or controlled by the owner of, and found on, the premises. State v. O'Brien, 223 Wis. 2d 303, 588 N.W.2d 8 (1999).
The "emergency doctrine" justifies a warrantless search when an officer is actually motivated by a perceived need to render aid and a reasonable person under the circumstances would have thought an emergency existed. State v. Richter, 224 Wis. 2d 814, 592 N.W.2d 310 (Ct. App. 1999).
Reasonable suspicion justifying an investigative stop may be based on an anonymous tip that does not predict future behavior. The key concern is the tipster's veracity. Officers' corroboration of readily observable information supports a finding that because the tipster was correct about innocent activities, he or she is probably correct about the ultimate fact of criminal activity. State v. Williams, 225 Wis. 2d 159, 591 N.W.2d 823 (1999).
A traffic stop must be based on probable cause, not reasonable suspicion. If the facts support a violation only under a legal misinterpretation, no violation has occurred, and by definition there can be no probable cause that a violation has occurred. State v. Longcore, 226 Wis. 2d 1, 594 N.W.2d 412 (Ct. App. 1999).
Being in a high crime area, making brief contact with a car, and hanging around a neighborhood each standing alone would not create reasonable suspicion justifying a Terry stop. When these events occurred in sequence and were considered with the officers training and experience, the reputation of the neighborhood, and the time of day, there was enough to create reasonable suspicion. State v. Allen, 226 Wis. 2d 66, 593 N.W.2d 504 (Ct. App. 1999).
Once a justifiable stop is made, the scope of the officer's inquiry may be broadened beyond the original purpose for which the person was stopped if additional particularized and objective, suspicious factors come to the officer's attention. A picture of a mushroom on the defendant's wallet, his appearance of nervousness, and the lateness of the hour were insufficient factors to extend a stop. State v. Betow, 226 Wis. 2d 90, 593 N.W.2d 499 (Ct. App. 1999). See also State v. Gammons, 2001 WI App 36, 241 Wis. 2d 296, 625 N.W.2d 623.
The owner of a commercial property has a reasonable expectation of privacy in those areas immediately surrounding the property only if affirmative steps have been taken to exclude the public. State v. Yakes, 226 Wis. 2d 425, 595 N.W.2d 108 (Ct. App. 1999).
A home's backyard and back door threshold were within the home's curtilage; an officer's warrantless entry was unlawful and evidence seized as a result of the entry was subject to suppression. State v. Wilson, 229 Wis. 2d 256, 600 N.W.2d 14 (Ct. App. 1999).
When the 2 other occupants of a vehicle had already been searched without any drugs being found, a search of the 3rd occupant based solely on the odor of marijuana was made with probable cause and was reasonable. State v. Mata, 230 Wis. 2d 567, 602 N.W.2d 158 (Ct. App. 1999).
A probation officer may search a probationer's residence without a warrant if the officer has reasonable grounds to believe the terms of probation are being violated, but the officer may not conduct a warrantless search as a subterfuge to further a criminal investigation to help the police evade the usual warrant and probable cause requirements. State v. Hajicek, 230 Wis. 2d 697, 602 N.W.2d 93 (Ct. App. 1999).
The risk that evidence will be destroyed is an exigent circumstance that may justify a warrantless search. When suspects are aware of the presence of the police, that risk increases. The seriousness of the offense as determined by the overall penalty structure for all potentially chargeable offenses also affects whether exigent circumstances justify a warrantless search. State v. Hughes, 2000 WI 24, 233 Wis. 2d 280, 607 N.W.2d 621.
Police officers do not need to choose between completing a protective frisk and handcuffing a suspect in a field investigation. They may do both. State v. McGill, 2000 WI 38, 234 Wis. 2d 560, 609 N.W.2d 795.
A frisk of a motor vehicle passenger that occurred 25 minutes after the initial stop that was a precautionary measure, not based on the conduct or attributes of the person frisked, was unreasonable. State v. Mohr, 2000 WI App 111, 235 Wis. 2d 220, 613 N.W.2d 186.
When a vehicle passenger has been seized pursuant to a lawful traffic stop, the seizure does not become unreasonable because an officer asks the passenger for identification. The passenger is free to refuse to answer, and refusal will not justify prosecution nor give rise to reasonable suspicion of wrongdoing. However, if the passenger chooses to answer falsely, the passenger can be charged with obstruction. State v. Griffith, 2000 WI 72, 236 Wis. 2d 48, 613 N.W.2d 72.
"Hot pursuit", defined as immediate or continuous pursuit of a suspect from a crime scene is an exigent circumstance justifying a warrantless search. An officer is not required to personally observe the crime or fleeing suspect. State v. Richter, 2000 WI 58, 235 Wis. 2d 524, 612 N.W.2d 29.
The property of a passenger in a motor vehicle may be searched when the police have validly arrested the driver but do not have a reasonable basis to detain or probable cause to arrest the passenger. State v. Pallone, 2000 WI 77, 236 Wis. 2d 162, 613 N.W.2d 568.
The search of a crawl space in a ceiling, which was located in an area where police had heard much activity, was large enough to hide a person, and was secured by screws that had to be removed with a screwdriver, was a reasonable "protective sweep" to search for persons who would pose a threat to the police as they executed an arrest warrant for a murder suspect. State v. Blanco, 2000 WI App 119, 237 Wis. 2d 395, 614 N.W.2d 512.
A police officer performing a Terry stop and requesting identification could perform a limited search for identifying papers when the information received by the officer was not confirmed by police records, the intrusion on the suspect was minimal, the officer observed that the suspect's pockets were bulging, and the officer had experience with persons who claimed to have no identification when in fact they did. State v. Black, 2000 WI App 175, 238 Wis. 2d 203, 617 N.W.2d 210.
The Paterson community caretaker exception justified a warrantless entry during an emergency detention of a mentally ill person who was threatening suicide. A protective sweep of the premises while acting as a community caretaker was reasonable. State v. Horngren, 2000 WI App 177, 238 Wis. 2d 347, 617 N.W.2d 508.
A warrantless blood draw is permissible when: 1) the blood is taken to obtain evidence of intoxication from a person lawfully arrested; 2) there is a clear indication that evidence of intoxication will be produced; 3) the method used is reasonable and performed in a reasonable manner; and 4) the arrestee presents no reasonable objection. State v. Thorstad, 2000 WI App 199, 238 Wis. 2d 666, 618 N.W.2d 240.
That a driver stopped at a stop sign for a few seconds longer than normal, that it was late in the evening, and that there was little traffic did not give rise to a reasonable suspicion that the driver was committing an unlawful act. State v. Fields, 2000 WI App 218, 239 Wis. 2d 38, 619 N.W.2d 279.
A warrantless entry need not be subjectively motivated solely by a perceived need to render aid and assistance in order for the "emergency doctrine" to apply. A dual motivation of investigating a potential crime and rendering aid and assistance may be present. State v. Rome, 2000 WI App 243, 239 Wis. 2d 491, 620 N.W.2d 225.
Whether a search is a probation search, which may be conducted without a warrant, or a police search, which may not, is a question of constitutional fact to be reviewed in a 2-step review of historical and constitutional fact. A determination of reasonableness of the search must also be made. A search is reasonable if the probation officer has reasonable grounds to believe that the probationer has contraband. Cooperation with police officers does not change a probation search into a police search. State v. Hajicek, 2001 WI 3, 240 Wis. 2d 349, 620 N.W.2d 781.
In light of the reduced expectation of privacy that applies to property in an automobile, the search of a vehicle passenger's jacket based upon the driver's consent to the search of the vehicle was reasonable. State v. Matejka, 2001 WI 5, 241 Wis. 2d 52, 621 N.W.2d 891.
Before the government may invade the sanctity of the home, it must demonstrate exigent circumstances that overcome the presumption of unreasonableness that attaches to all warrantless home entries. Reluctance to find an exigency is especially appropriate when the underlying offense for which there is probable cause to arrest is relatively minor. State v. Kryzaniak, 2001 WI App 44, 241 Wis. 2d 358, 624 N.W.2d 389.
Under Florida v. J.L, an anonymous tip giving rise to reasonable suspicion must bear indicia of reliability. That the tipster's anonymity is placed at risk indicates the the informant is genuinely concerned and not a fallacious prankster. Corroborated aspects of the tip also lend credibility; the corroborated actions of the suspect need be inherently criminal in and of themselves. State v. Williams, 2001 WI 21, 241 Wis. 2d 631, 623 N.W.2d 106.
An anonymous tip regarding erratic driving from another driver celling from a cell phone contained sufficient indicia of reliability to justify an investigative stop when the informant was exposed to possible identification, and therefore possible arrest if the tip proved false; the tip reported contemporaneous and verifiable observations regarding the driving, location, and vehicle; and the officer verified many of the details in the tip. That the tip reasonably suggested intoxicated driving created an exigency strongly in favor of immediate police investigation without the necessity that the officer personally observe erratic driving, State v. Rutzinski, 2001 WI 22, 241 Wis. 2d 729, 623 N.W.2d 516.
The state constitution does not provide greater protection under the automobile exception for warrantless searches than the 4th amendment. The warrantless search of a vehicle is allowed when there is probable cause to search the vehicle and the vehicle is mobile. The exception apples to vehicles that are not in public places. There is no requirement that obtaining a warrant be impracticable. State v. Marquardt, 2001 WI App 219, 247 Wis. 2d 765, 635 N.W.2d 188.
Whether exigent circumstances existed justifying a warrantless entry to prevent destruction of evidence after the defendant saw, and retreated from, a plain-clothes officer was not a question of whether the defendant knew that the detective was a police officer, but whether it was reasonable for the officer to believe that he had been identified and that the suspect would destroy evidence as a consequence. State v. Garrett, 2001 WI App 240, 248 Wis. 2d 61, 635 N.W.2d 615.
For the warrantless search of an area made incident to the making of an arrest to be justified as a protective sweep to protect the safety of police officers where the area searched was not in the immediate vicinity of where the arrest was made, there must be articulable facts that would warrant a reasonably prudent officer to believe that the area harbored an individual posing a danger to the officers. State v. Garrett, 2001 WI App 240, 248 Wis. 2d 61, 635 N.W.2d 615.
When a caller identifies himself or herself by name, placing his or her anonymity at risk, and the totality of the circumstances establishes a reasonable suspicion that criminal activity may be afoot, the police may execute a lawful investigative stop. Whether the caller gave correct identifying information or the police ultimately could have verified the the information, the caller, by providing the information, risked that his or her identity would be discovered and cannot be considered anonymous. State v. Sisk, 2001 WI App 182, 247 Wis. 2d 443, 634 N.W.2d 877.
The need to transport a person in a police vehicle is not an exigency that justifies a search for weapons. More specific and articulable facts must be shown to support a Terry frisk. While a routine pat-down of a person before a police officer places the person in a squad car is wholly reasonable, evidence gleaned from the search will only be admissible if there are particularized issues of safety concerns about the defendant. State v. Hart, 2001 WI App 283, 249 Wis. 2d 329, 639 N.W.2d 213.
Although no traffic violation occurred, a traffic stop to make contact with the defendant was reasonable when police had reasonable suspicion that the defendant had previously been involved in a crime and the defendant had intentionally avoided police attempts to engage her in voluntary conversation. State v. Olson, 2001 WI App 284, 249 Wis. 2d 391, 639 N.W.21d 207.
It was reasonable to conduct a Terry search of a person who knocked on the door of a house while it was being searched for drugs pursuant to a warrant. State v. Kolp, 2002 WI App 17, 250 Wis. 2d 296, 640 N.W.2d 551.
A warrantless blood draw by a physician in a jail setting may be unreasonable if it invites an unjustified element of personal risk of pain and infection. Absent evidence of those risks, a blood draw under those circumstances was reasonable. State v. Daggett, 2002 WI App 32, 250 Wis. 2d 112, 640 N.W.2d 546.
Terry applies to confrontations between the police and citizens in public places only. For private residences and hotels, in the absence of a warrant, the police must have probable cause and exigent circumstances or consent to justify an entry. Reasonable suspicion is not a prerequisite to an officer's seeking consent to enter a private dwelling. If the police have lawfully entered a dwelling with valid consent and have a reasonable suspicion that a suspect is armed, a Terry pat-down for weapons is permissible. State v. Stout, 2002 WI App 41, 250 Wis. 2d 768, 641 N.W.2d 474.
A warrantless nonconsensual blood draw from a person arrested, with probable cause, for drunk driving is constitutional based on the exigent circumstances exception to the warrant requirement of the 4th amendment, even if the person offers to submit to a chemical test other than the blood test chosen by law enforcement, provided that the blood draw complies with the factors enumerated in Bohling. State v. Krajewski, 2002 WI 97, 255 Wis. 2d 98, 648 N.W.2d 385.
A warrantless search of a home is presumptively unreasonable, but exigent circumstances that militate against delay in getting a warrant can justify immediate entry and search. Whether the officers acted reasonably in entering the house without a warrant is measured against what a reasonable police officer would reasonably believe under the circumstances. State v. Londo, 2002 WI App 90, 252 Wis. 2d 731, 643 N.W.2d 869.
Canine sniffs are not searches within the meaning of the 4th amendment, and police are not required to have probable cause or reasonable suspicion before walking a dog around a vehicle for the purpose of detecting drugs in the vehicle's interior. A dog's alert on an object provides probable cause to search that object, provided that the dog is trained in narcotics detection and has demonstrated a sufficient level of reliability in detecting drugs in the past and the officer with the dog is familiar with how it reacted when it smelled contraband. State v. Miller, 2002 WI App 150, ___ Wis. 2d ___, 647 N.W.2d 348.
An arrest made in hot pursuit constitutes an exigent circumstance required for a warrantless entry, but the exception is limited to the hot pursuit of fleeing felons. State v. Mikkelson, 2002 WI App 152, ___ Wis. 2d ___, 647 N.W.2d 421.
A reasonable probation search is lawful even if premised, in part, on information obtained in violation of the 4th amendment by law enforcement. State v. Wheat, 2002 WI App 153, ___ Wis. 2d ___, 647 N.W.2d 441.
But What of Wisconsin's Exclusionary Rule? The Wisconsin Supreme Court Accepts Apparent Authority to Consent as Grounds for Warrantless Searches. Schmidt. 83 MLR 299 (1999).
A warrantless, non-exigent, felony arrest in public was constitutional despite the opportunity to obtain a warrant. United States v. Watson, 423 U.S. 411.
Where a driver was stopped because of expired license plates, a police order to get out of the car was reasonable and a subsequent "pat down" based on an observed bulge under the driver's jacket resulted in the legal seizure of an unlicensed revolver. Pennsylvania v. Mimms, 434 U.S. 106 (1977).
A burning building clearly presents an exigency rendering a warrantless entry reasonable, and fire officials need no warrant to remain in a building for a reasonable time to investigate the cause of the fire after it is extinguished. Michigan v. Tyler, 436 U.S. 499 (1978)
The warrantless installation of a pen register, that recorded telephone numbers called but not the contents of the calls, did not violate the 4th amendment. Smith v. Maryland, 442 U.S. 735 (1979).
A warrantless search of a suitcase in the trunk of a taxi was unconstitutional. Arkansas v. Sanders, 442 U.S. 753 (1979).
Police may not make a warrantless and nonconsensual entry into suspect's home in order to make a routine felony arrest. Payton v. New York, 445 U.S. 573 (1980).
The fact that police had lawful possession of pornographic film boxes did not give them authority to search their contents. Walter v. United States, 447 U.S. 649 (1980).
The search of a jacket lying in the passenger compartment of a car was incident to a lawful custodial arrest that justified th infringement of any privacy interest the arrestee may have. New York v. Belton, 453 U.S. 454 (1981).
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 (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 (1982).
A warrantless search by arson investigators of defendant's fire-damaged home that was not a continuation of an earlier search was unconstitutional. Michigan v. Clifford, 464 U.S. 287 (1984).
Where a damaged shipping package was examined by company employees who discovered white powder, a subsequent warrantless field test by police was constitutional. U.S. v. Jacobsen, 466 U.S. 109 (1984).
The "open fields" doctrine discussed. Oliver v. U.S. 466 U.S. 170 (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 (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 (1985).
Where officers were entitled to seize packages in a vehicle and could have searched them immediately without a warrant, a warrantless search of the packages 3 days later was reasonable. United States v. Johns, 469 U.S. 478 (1985).
The vehicle exception for warrantless search applies to motor homes. California v. Carney, 471 U.S. 386 (1985).
The good faith exception to the exclusionary rule applies where an officer reasonably relies upon a statute allowing a warrantless administrative search that was subsequently ruled unconstitutional. Illinois v. Krull, 480 U.S. 340 (1987).
A protective sweep of a residence in conjunction with an arrest is permissible if law enforcement reasonably believes that the area harbors an individual posing a danger to officers or others. Maryland v. Buie, 494 U.S. 325, 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 L. Ed. 2d 112 (1990).
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, 114 L. Ed. 2d 49 (1991).
An officer's opening of a closed bag found on the floor of a suspect's car during a search of the car made with suspect's consent was not unreasonable. Florida v. Jimeno, 500 U.S. 248, 114 L. Ed. 2d 297 (1991).
There shall be one rule governing all automobile searches. The police may search the car and all containers within it without a warrant where they have probable cause to believe contain contraband or evidence is contained. California v. Acevedo, 500 U.S. 565, 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, 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, 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, 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, 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 it's 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, 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, 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, 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, 144 L. Ed. 2d 442 (1999).
There is no murder scene exception to the warrant requirement. Flippo v. West Virginia, 528 U.S. 11, 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, 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 to identify a person. Florida v. J.L. 529 U.S. 266, 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, 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, prevented the man from entering the home for about 2 hours until a search warrant could be obtained. Illinois v. McArthur, 531 US 326, 148 LEd2d 838 (2001).
A state hospital could not test maternity patients for cocaine and then turn the results over to law enforcement authorities without patient consent. The interest of using the threat of criminal sanctions to deter pregnant women from using cocaine does not justify a departure from the rule that a nonconsensual search is unconstitutional if not authorized by a warrant. Ferguson v. City of Charleston, 525 US 67, 149 LEd 2d 205 (2001).
If an officer has probable cause to believe a person has committed even a very minor criminal offense that does not breach the peace, the officer may, without violating the 4th amendment, arrest the offender without the need to balance the circumstances involved in the particular situation. Atwater v. City of Lago Vista, 532 US 318, 149 L. Ed. 2d 549 (2001)
Obtaining, by sense enhancing technology like infrared imaging, information regarding the interior of a home that could otherwise not be obtained without physical intrusion into a constitutionally protected area is a search presumptively unreasonable without a warrant. Kyllo v. U.S. 533 U.S. 27, 150 L. Ed. 2d 94 (2001).