The principles of Terry, 392 U.S. 1 (1968), permit a state to require a suspect to disclose his or her name in the course of a Terry stop and allow imposing criminal penalties for failing to do so. Hiibel v. Sixth Judicial District Court, 542 U.S. 177, 124 S. Ct. 2451, 159 L. Ed 2d 292 (2004). The 4th amendment does not require reasonable, articulable suspicion to justify using a drug-detection dog to sniff a vehicle during a legitimate traffic stop. The use of a well-trained narcotics-detection dog that does not expose noncontraband items that otherwise would remain hidden from public view during a lawful traffic stop, generally does not implicate legitimate privacy interests. Illinois v. Caballes, 543 U.S. 405, 125 S. Ct. 834, 160 L. Ed. 2d 842 (2004). Police may enter a home without a warrant when they have an objectively reasonable basis for believing that an occupant is seriously injured or imminently threatened with such injury. An action is reasonable under the 4th amendment, regardless of the individual officer’s state of mind, as long as the circumstances, viewed objectively, justify the action. Brigham City v. Stuart, 547 U.S. 398, 126 S. Ct. 1943, 164 L. Ed. 2d 650 (2006). Warrantless arrests for crimes committed in the presence of an arresting officer are reasonable under the U.S. Constitution, and while states are free to regulate such arrests however they desire, state restrictions do not alter the 4th amendment’s protections. Virginia v. Moore, 553 U.S. 164, 128 S. Ct. 1598, 170 L. Ed. 2d 559 (2008). In a traffic-stop setting, the first Terry, 392 U.S. 1 (1968), condition—a lawful investigatory stop—is met whenever it is lawful for police to detain an automobile and its occupants pending inquiry into a vehicular violation. The police need not have, in addition, cause to believe any occupant of the vehicle is involved in criminal activity. To justify a patdown of the driver or a passenger during a traffic stop, however, the police must harbor reasonable suspicion that the person subjected to the frisk is armed and dangerous. Arizona v. Johnson, 555 U.S. 323, 129 S. Ct. 781, 172 L. Ed. 2d 694 (2009). Belton, 453 U.S. 454 (1981), does not authorize a vehicle search incident to a recent occupant’s arrest after the arrestee has been secured and cannot access the interior of the vehicle. Police are authorized to search a vehicle incident to a recent occupant’s arrest only when the arrestee is unsecured and within reaching distance of the passenger compartment at the time of the search. Consistent with Thornton, 541 U.S. 615 (2004), circumstances unique to the automobile context justify a search incident to arrest when it is reasonable to believe that evidence of the offense of arrest might be found in the vehicle. Arizona v. Gant, 556 U.S. 332, 129 S. Ct. 1710, 173 L. Ed. 2d 485 (2009). The T.L.O., 469 U.S. 325 (1985), concern to limit a school search to a reasonable scope requires reasonable suspicion of danger or a resort to hiding evidence of wrongdoing in underwear before a searcher can reasonably make the quantum leap from a search of outer clothes and backpacks to exposure of intimate parts. The meaning of such a search, and the degradation its subject may reasonably feel, place a search that intrusive in a category of its own demanding its own specific suspicions. Safford Unified School District No. 1 v. Redding, 557 U.S. 364, 129 S. Ct. 2633, 174 L. Ed. 2d 354 (2009). A government employer had the right, under the circumstances of the case, to read text messages sent and received on a pager the employer owned and issued to an employee. The privacy of the messages was not protected by the ban on “unreasonable searches and seizures” found in the 4th amendment. Because the search was motivated by a legitimate work related purpose, and because it was not excessive in scope, the search was reasonable. Ontario v. Quon, 560 U.S. 746, 130 S. Ct. 2619, 177 L. Ed. 2d 216 (2010). Warrantless searches are allowed when the circumstances make it reasonable, within the meaning of the 4th amendment, to dispense with the warrant requirement. The exigent circumstances rule justifies a warrantless search when the conduct of the police preceding the exigency is reasonable in the same sense. When the police do not create the exigency by engaging or threatening to engage in conduct that violates the 4th amendment, warrantless entry to prevent the destruction of evidence is reasonable and thus allowed. Kentucky v. King, 563 U.S. 452, 131 S. Ct. 1849, 179 L. Ed. 2d 865 (2011). The government’s installation of a global-positioning-system (GPS) device on a target’s vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a “search.” United States v. Jones, 565 U.S. 400, 132 S. Ct. 945, 181 L. Ed. 2d 911 (2012). Whether an official protected by qualified immunity may be held personally liable for an allegedly unlawful official action generally turns on the objective legal reasonableness of the action, assessed in light of the legal rules that were clearly established at the time the action was taken. When an alleged 4th amendment violation involves a search or seizure pursuant to a warrant, the fact that a neutral magistrate has issued a warrant is the clearest indication that the officers acted in an objectively reasonable manner. There is a narrow exception allowing suit when it is obvious that no reasonably competent officer would have concluded that a warrant should issue. Messerschmidt v. Millender, 565 U.S. 535, 132 S. Ct. 1235, 182 L. Ed. 2d 47 (2012). Generally, every detainee who will be admitted to the general jail population may be required to undergo a close visual inspection while undressed. Undoubted security imperatives involved in jail supervision override the assertion that some detainees must be exempt from these invasive procedures absent reasonable suspicion of a concealed weapon or other contraband. Deference must be given to the officials in charge of the jail unless there is substantial evidence demonstrating their response to the situation is exaggerated. Florence v. Board of Chosen Freeholders of County of Burlington, 566 U.S. 318, 132 S. Ct. 1510, 182 L. Ed. 2d 566 (2012). The categorical authority to detain incident to the execution of a search warrant must be limited to the immediate vicinity of the premises to be searched. A spatial constraint defined by the immediate vicinity of the premises to be searched is therefore required for detentions incident to the execution of a search warrant. Limiting the rule in Summers, 452 U.S. 692 (1981), to the area in which an occupant poses a real threat to the safe and efficient execution of a search warrant ensures that the scope of the detention incident to a search is confined to its underlying justification. Once an occupant is beyond the immediate vicinity of the premises to be searched, the search-related law enforcement interests are diminished and the intrusiveness of the detention is more severe. Bailey v. United States, 568 U.S. 186, 133 S. Ct. 1031, 185 L. Ed. 2d 19 (2013). Using a drug-sniffing dog on a homeowner’s porch to investigate the contents of the home is a “search” within the meaning of the 4th amendment. A police officer not armed with a warrant may approach a home and knock, precisely because that is no more than any private citizen might do. But introducing a trained police dog to explore the area around the home in hopes of discovering incriminating evidence is something else. There is no customary invitation to do that. Florida v. Jardines, 569 U.S. 1, 133 S. Ct. 1409, 185 L. Ed. 2d 495 (2013). Natural metabolization of alcohol in the bloodstream does not present a per se exigency that justifies an exception to the warrant requirement for nonconsensual blood testing in all drunk-driving cases. Consistent with general 4th amendment principles, exigency in this context must be determined case by case based on the totality of the circumstances. Missouri v. McNeely, 569 U.S. 141, 133 S. Ct. 1552, 185 L. Ed. 2d 696 (2013). Police officers must generally secure a warrant before conducting a search of the information on a cell phone seized from an individual who has been arrested. Law enforcement officers remain free to examine the physical aspects of a phone to ensure that it will not be used as a weapon. Once an officer has secured a phone and eliminated any potential physical threats, however, data on the phone can endanger no one. Riley v. California, 573 U.S. 373, 134 S. Ct. 2473, 189 L. Ed. 2d 430 (2014). In light of Jones, 565 U.S. 400 (2012), and Jardines, 569 U.S. 1 (2013), it follows that a state conducts a search when it attaches a device to a person’s body, without consent, for the purpose of tracking that individual’s movements. That conclusion, however, does not decide the ultimate question of the program’s constitutionality. The 4th amendment prohibits only unreasonable searches. Grady v. North Carolina, 575 U.S. 306, 135 S. Ct. 1368, 191 L. Ed. 2d 459 (2015). A police stop exceeding the time needed to handle the matter for which the stop was made violates the constitution’s shield against unreasonable seizures. A seizure justified only by a police-observed traffic violation, therefore, becomes unlawful if it is prolonged beyond the time reasonably required to complete the mission of issuing a ticket for the violation. Rodriguez v. United States, 575 U.S. 348, 135 S. Ct. 1609, 191 L. Ed. 2d 492 (2015). The attenuation doctrine applies when an officer makes an unconstitutional investigatory stop; learns during that stop that the suspect is subject to a valid arrest warrant; and proceeds to arrest the suspect and seize incriminating evidence during a search incident to that arrest. The evidence the officer seized as part of the search incident to arrest is admissible because the officer’s discovery of the arrest warrant attenuated the connection between the unlawful stop and the evidence seized incident to arrest. Utah v. Strieff, 579 U.S. 232, 136 S. Ct. 2056, 195 L. Ed. 2d 400 (2016). A breath test, but not a blood test, may be administered as a search incident to a lawful arrest for drunk driving. As in all cases involving reasonable searches incident to arrest, a warrant is not needed in this situation. The 4th amendment permits warrantless breath tests incident to arrests for drunk driving. The impact of breath tests on privacy is slight, and the need for blood alcohol content testing is great. Blood tests are significantly more intrusive, and their reasonableness must be judged in light of the availability of the less invasive alternative of a breath test. Birchfield v. North Dakota, 579 U.S. 438, 136 S. Ct. 2160, 195 L. Ed 2d 560 (2016). The automobile exception to the 4th amendment does not permit a police officer, uninvited and without a warrant, to enter the curtilage of a home in order to search a vehicle parked therein. Collins v. Virginia, 584 U.S. ___, 138 S. Ct. 1663, 201 L. Ed. 2d 9 (2018). Individuals have a reasonable expectation of privacy in the whole of their physical movements, and an individual maintains a legitimate expectation of privacy in the record of the individual’s physical movements as captured through cell-site location information. The government conducts a search under the 4th amendment when the government accesses historical cell phone records that provide a comprehensive chronicle of a user’s past movements. Carpenter v. United States, 585 U.S. ___, 138 S. Ct. 2206, 201 L. Ed. 2d 507 (2018). Under the third-party doctrine, a person has no legitimate expectation of privacy in information the person voluntarily turns over to third parties. However, given the unique nature of cellphone location records, the fact that the information is held by a third party does not by itself overcome a user’s claim to 4th amendment protection. Whether the government employs its own surveillance technology or leverages the technology of a wireless carrier, an individual maintains a legitimate expectation of privacy in the record of the individual’s physical movements as captured through cell-site location information, and a warrant is required in the rare case where a suspect has a legitimate privacy interest in records held by a third party. Carpenter v. United States, 585 U.S. ___, 138 S. Ct. 2206, 201 L. Ed. 2d 507 (2018). A police officer did not violate the 4th amendment by initiating an investigative traffic stop after running a vehicle’s license plate and learning that the registered owner had a revoked driver’s license when the officer lacked information negating an inference that the owner was the driver of the vehicle. Kansas v. Glover, 589 U.S. ___, 140 S. Ct. 1183, 206 L. Ed. 2d 412 (2020). “Community caretaking” duties do not create a standalone doctrine that justifies warrantless searches and seizures in the home. Caniglia v. Strom, 593 U.S. ___, 141 S. Ct. 1596, 209 L. Ed. 2d 604 (2021). The need to pursue a misdemeanant does not trigger a categorical rule allowing home entry, even absent a law enforcement emergency. When the nature of the crime, the nature of the flight, and surrounding facts present no such exigency, officers must respect the sanctity of the home—which means that they must get a warrant. Lange v. California, 594 U.S. ___, 141 S. Ct. 2011, 210 L. Ed. 2d 486 (2021). Within the meaning of the 4th amendment, domestic animals are effects and the killing of a companion dog constitutes a seizure, which is constitutional only if reasonable. Viilo v. Eyre, 547 F.3d 707 (2008). Given how slight is the incremental loss of privacy from having to wear an anklet monitor, and how valuable to society the information collected by the monitor is, s. 301.48 does not violate the 4th amendment. The terms of supervised release, probation, and parole often authorize searches by probation officers without the officers’ having to obtain warrants. Such warrantless searches do not violate the 4th amendment as long as they are reasonable. Such monitoring of sex offenders is permissible if it satisfies the reasonableness test applied in parolee and special-needs cases. Wisconsin’s ankle monitoring of the defendant is reasonable. Belleau v. Wall, 811 F.3d 929 (2016). See also Braam v. Carr, 37 F.4th 1269 (2022).