Police are not prevented from ever using evidence gleaned from an illegal search in a subsequent and independent investigation. When the later investigation is not prompted by the information obtained in the earlier search, the information may be used. State v. Simmons, 220 Wis. 2d 775, 585 N.W.2d 165 (Ct. App. 1998), 97-1861. The odor of a controlled substance provides probable cause to arrest when the odor is unmistakable and may be linked to a specific person under the circumstances of the discovery of the odor. The odor of marijuana emanating from a vehicle established probable cause to arrest the sole occupant of the vehicle. State v. Secrist, 224 Wis. 2d 201, 589 N.W.2d 387 (1999), 97-2476. See also State v. Moore, 2023 WI 50, 408 Wis. 2d 16, 991 N.W.2d 412, 21-0938. Police have authority under a valid search warrant to enter unoccupied premises if the search is otherwise reasonable under the circumstances. Knocking and announcing is not required. State v. Moslavac, 230 Wis. 2d 338, 602 N.W.2d 150 (Ct. App. 1999), 98-3037. “Probable cause to believe” does not refer to a uniform degree of proof, but instead varies in degree at different stages of the proceedings. County of Jefferson v. Renz, 231 Wis. 2d 293, 603 N.W.2d 541 (1999), 97-3512. The test for finding probable cause to issue a warrant is not whether the inference drawn from the supporting affidavit is the only reasonable inference. The test is whether the inference drawn is a reasonable one. State v. Ward, 2000 WI 3, 231 Wis. 2d 723, 604 N.W.2d 517, 97-2008. Marijuana plants discovered while officers, although mistaken, believed they were executing a valid search warrant of an adjacent apartment were properly admitted into evidence. Because the officers were required to cease all searching when they discovered that they were not operating within the scope of the warrant, incriminating statements and evidence obtained thereafter were properly suppressed. A warrant obtained for the second apartment based on the discovery of the marijuana plants was based on untainted evidence, and additional evidence obtained thereunder was admissible. State v. Herrmann, 2000 WI App 38, 233 Wis. 2d 135, 608 N.W.2d 406, 99-0325. Police with an arrest warrant are authorized to enter a home if they have probable cause to believe that the person named in the warrant lives there and is present but not to enter a third-party’s residence where the police believe the person to be a visitor. State v. Blanco, 2000 WI App 119, 237 Wis. 2d 395, 614 N.W.2d 512, 98-3153. In searching a computer for items listed in a warrant, the police are entitled to examine all files to determine if their contents fall within the scope of the warrant. The first file containing evidence of other illegal activity is admissible under the plain view doctrine and is grounds for a warrant to search for more evidence of the second illegal activity. State v. Schroeder, 2000 WI App 128, 237 Wis. 2d 575, 613 N.W.2d 911, 99-1292. The constitutional validity of an unannounced entry in serving a warrant turns on whether the evidence introduced at the suppression hearing, including the facts known to the police but not included in the warrant application, was sufficient to establish a reasonable suspicion that knocking and announcing, under the circumstances, would be dangerous or futile or would inhibit the effective investigation of the crime. State v. Henderson, 2001 WI 97, 245 Wis. 2d 345, 629 N.W.2d 613, 99-2296. A good faith exception to the exclusionary rule is adopted for when police officers act in objectively reasonable reliance upon a warrant that had been issued by a detached and neutral magistrate. For the exception to apply, the state must show that the process used in obtaining the search warrant included a significant investigation and a review by either a police officer trained and knowledgeable in the requirements of probable cause and reasonable suspicion or a knowledgeable government attorney. State v. Eason, 2001 WI 98, 245 Wis. 2d 206, 629 N.W.2d 625, 98-2595. Whether tenants have a reasonable expectation of privacy in stairways and halls of rental property is to be determined by assessing each case on its individual facts and depends on whether the person has exhibited an actual subjective expectation of privacy in the area inspected and whether society is willing to recognize the expectation as reasonable. State v. Trecroci, 2001 WI App 126, 246 Wis. 2d 261, 630 N.W.2d 555, 00-1079. The timeliness of seeking a warrant depends upon the nature of the underlying circumstances and concepts. When the activity is of a protracted and continuous nature, the passage of time diminishes in significance. Factors like the nature of the criminal activity under investigation and the nature of what is being sought have a bearing on where the line between stale and fresh information should be drawn in a particular case. State v. Multaler, 2001 WI App 149, 246 Wis. 2d 752, 632 N.W.2d 89, 00-1846. Warrants for administrative or regulatory searches modify the conventional understanding of probable cause for warrants as the essence of the search is that there is no probable cause to believe a search will yield evidence of a violation. Refusal of consent is not a constitutional requirement for issuing the warrant, although it may be a statutory violation. Suppression only applies to constitutional violations. State v. Jackowski, 2001 WI App 187, 247 Wis. 2d 430, 633 N.W.2d 649, 00-2851. There is a presumption that a warrantless search of a private residence is per se unreasonable. A warrantless search requires probable cause, not reasonable suspicion. Although flight from an officer may constitute reasonable suspicion, it does not rise to probable cause. For probable cause, there must be a fair probability that contraband or evidence will be found in a particular place. State v. Rodriguez, 2001 WI App 206, 247 Wis. 2d 734, 634 N.W.2d 844, 00-2546. The absence of an oath or affirmation supporting the issuance of a warrant is not a mere technicality or matter of formality. Absence of an oath subjects evidence seized under the defective warrant to suppression. State v. Tye, 2001 WI 124, 248 Wis. 2d 530, 636 N.W.2d 473, 99-3331. If a telephone warrant application has not been recorded and there is no evidence of intentional or reckless misconduct on the part of law enforcement officers, a reconstructed application may serve as an equivalent of the record of the original application and can protect the defendant’s right to a meaningful appeal and ability to challenge the admission of evidence. Courts should consider the time between the application and the reconstruction, the length of the reconstructed segment in relation to the entire warrant request, if there were any contemporaneous written documents used to reconstruct the record, the availability of witnesses used to reconstruct the record, and the complexity of the segment reconstructed. The issuing judge’s participation may be appropriate. State v. Raflik, 2001 WI 129, 248 Wis. 2d 593, 636 N.W.2d 690, 00-1086. Probable cause to arrest may be based on hearsay that is shown to be reliable and emanating from a credible source. Thus information from a confidential informant may supply probable cause if the police know the informant to be reliable. State v. McAttee, 2001 WI App 262, 248 Wis. 2d 865, 637 N.W.2d 774, 00-2803. An affidavit in support of a search warrant is not a research paper or legal brief that demands citations for every proposition. An investigator’s detailed listing of the investigator’s sources of information and accompanying credentials, combined with the investigator’s indication that his opinion was based upon his training and research provided a sufficient foundation for the opinion the investigator gave in support of the warrant. State v. Multaler, 2002 WI 35, 252 Wis. 2d 54, 643 N.W.2d 437, 00-1846. Under Ellenbecker, 159 Wis. 2d 91 (1990), it was reasonable for an officer, who stopped a motorist whose vehicle and general appearance matched that of a criminal suspect, to make a report of the incident, even if the officer had already decided that the driver was not the suspect, and for that purpose it was reasonable to ask for the motorist’s name and identification. Once the motorist stated that the motorist had no identification, there was a reasonable ground for further detention. State v. Williams, 2002 WI App 306, 258 Wis. 2d 395, 655 N.W.2d 462, 02-0384. When the reasonableness of a no-knock entry is challenged, the state must present evidence of the circumstances at the time of warrant execution that would justify a no-knock entry. If the circumstances are described in the warrant application, the evidence might be testimony by an officer that nothing had come to the officer’s attention to lead them to believe that circumstances had changed. If the warrant application is silent or lacking in regard to circumstances that might render an announced entry dangerous or futile, the state may still justify a no-knock entry by showing that the officers possessed the requisite reasonable suspicion at the time of entry. State v. Whiting, 2003 WI App 101, 264 Wis. 2d 722, 663 N.W.2d 299, 02-1721. Otherwise innocent conduct can supply the required link in the chain to establish probable cause that a crime has or is about to be committed. Although an individual fact in a series may be innocent in itself, when considered as a whole, the facts may warrant further investigation. State v. Schaefer, 2003 WI App 164, 266 Wis. 2d 719, 668 N.W.2d 760, 01-2691. The existence of probable cause in the context of information provided by an anonymous tipster is determined by a totality-of-the-circumstances analysis. As applied to assessing the reliability of an anonymous tip, a deficiency in one factor may be compensated for by some other indicia of reliability when considered in the context of the totality of the circumstances. A recognized indicia of the reliability of an anonymous tip is police corroboration of details, particularly details involving predicted behavior. Probable cause may exist even if the predicted behavior corroborated by the police is, when viewed in isolation, innocent behavior. Police themselves need not observe suspicious behavior. State v. Sherry, 2004 WI App 207, 277 Wis. 2d 194, 690 N.W.2d 435, 03-1531. That an officer arrested the defendant for a crime that does not exist did not make the arrest illegal. The pertinent question is whether the arrest was supported by probable cause to believe the defendant committed a crime that does exist. State v. Repenshek, 2004 WI App 229, 277 Wis. 2d 780, 691 N.W.2d 369, 03-3089. Under Leon, 468 U.S. 897 (1984), an officer cannot be expected to question a magistrate’s probable-cause determination or judgment that the form of the warrant is technically sufficient except when: 1) the magistrate in issuing the warrant was misled by information in an affidavit that the affiant knew was false or would have known was false except for a reckless disregard of the truth; 2) the issuing magistrate wholly abandoned the magistrate’s judicial role; 3) an affidavit is so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable; or 4) the warrant is so facially deficient that the executing officers cannot reasonably presume it to be valid. State v. Marquardt, 2005 WI 157, 286 Wis. 2d 204, 705 N.W.2d 878, 04-0958. The inquiry into whether a warrant affidavit is so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable under Leon, 468 U.S. 897 (1984), must be different from the inquiry into whether the facts in the warrant application are clearly insufficient to support a determination of probable cause. That the warrant application was insufficient to support the warrant-issuing judge’s probable cause determination does not mean that the affidavit in support of the warrant was lacking in indicia of probable cause within the meaning of Leon. State v. Marquardt, 2005 WI 157, 286 Wis. 2d 204, 705 N.W.2d 878, 04-0958.