By of the

The Wisconsin Supreme Court on Thursday continued its recent string of Fourth Amendment decisions, this time in two divided rulings upholding warrantless searches to track suspects through their cellphone location.

In a Milwaukee case, the court affirmed the conviction of a man discovered in his mother's apartment through use of a portable cell tower device known as a stingray. In a Kenosha case, the court said emergencies, good faith reliance or harmless error were reasons to uphold the homicide conviction of a man caught in Arkansas after police tracked his cellphone with the help of his service provider.

Chief Justice Shirley Abrahamson, who dissented in both cases, said that each clearly involved a search that should and could have been conducted after getting a warrant, and that she would have suppressed evidence gathered as a result in each instance.

Almost all the justices writing opinions in the cases described the growing intersection of privacy and technology, and seemed to recognize citizens' growing dependence on cellphones, and their general expectation of privacy in using them. But the prevailing opinion in each sided with law enforcement, which also relies increasingly on the same technology to help solve crimes quickly.

Bobby L. Tate was convicted of a 2009 fatal shooting outside Mother's Foods. Milwaukee police used information about which cell towers his phone was connecting to, which helped them get a general idea of his location. They then used a portable device called a stingray, which acts like a fake cell tower as it gathers data from nearby cellphones to narrow a search. In this case, officers were led to his mother's apartment, where Tate was arrested.

Police knew Tate's phone number because witnesses said he had purchased the phone from Mother's. A prosecutor had applied for authorization to track the phone, which a judge approved, but it was not a search warrant. Tate later argued the search was akin to officers using a GPS tracking device and was unconstitutional without a warrant.

Writing for a 5-2 majority in the Tate case, Justice Patience Roggensack found that a judge's order for a cellphone service records was close enough in spirit to a search warrant because it was based on probable cause.

In the Kenosha case, five justices wrote separate opinions upholding the conviction of Nicolas Subdiaz-Osorio. Justice Ann Walsh Bradley, who often joins Abrahamson's opinions, agreed with the chief justice that the tracking of Subdiaz-Osorio was a search, but determined that given other factors in his case, the decision not to grant his motion to suppress was harmless error.

In the Tate case, Bradley joined in most, but not all, of Abrahamson's dissent.

"Unlike the majority opinion in Tate and Justice Prosser's lead opinion in Subdiaz-Osorio, I conclude that government access to cellphone location data in the present cases is a search within the meaning of the Constitutions that requires a warrant, and that the warrant must comply with the existing directly applicable statutes," Abrahamson wrote.

"The warrant in Tate did not comply with the existing statutes and is invalid. No warrant was obtained in Subdiaz-Osorio."

Earlier this month, the court issued opinions upholding the warrantless search of a briefcase during a traffic stop, despite the owner asking, "Got a warrant for that?" and striking down a search that followed a traffic stop based on a defective taillight, when only one of multiple bulbs in a taillight panel was not working.