Media Center

Wisconsin Supreme Court Concludes That Madison Police Obtained A Valid Warrant Authorizing Placement Of GPS Tracking Device On Car Of Stalking Suspect


MADISON - This morning, the Wisconsin Supreme Court concluded that Madison police acted according to law when they obtained a Dane County circuit court order authorizing the installation of a Global Positioning System (GPS) tracking device on the car of Michael A. Sveum, a man whom they suspected of stalking a former girlfriend.  Information obtained from the GPS tracker led to Sveum's later conviction for aggravated stalking.  Wisconsin's highest court assumed, but did not specifically decide, that the installation and monitoring of the GPS tracker constituted a search or seizure under both United States and Wisconsin Constitutions.


Attorney General J.B. Van Hollen, whose office represented the State of Wisconsin in the Wisconsin Supreme Court, supported the Court's decision.  "GPS technology provides Wisconsin law enforcement officers with another powerful crime-fighting tool," said Van Hollen.  "Here, Madison police obtained a valid warrant and acted reasonably in placing the GPS tracker on Sveum's car and in obtaining the data.  Sveum's rights were scrupulously protected."


Sveum had a previous criminal conviction for stalking his former girlfriend.  After receiving information that Sveum had renewed his stalking, Madison police obtained a circuit court order authorizing them to install and monitor a GPS tracking device on Sveum's car.  Over the 60-day period specified in the order, police installed, monitored and replaced several GPS trackers.  Data recovered from the devices provided incriminating evidence of Sveum's movements and he was eventually convicted of aggravated stalking.


Sveum challenged the validity of the circuit court order authorizing the installation and monitoring of the GPS tracker.  In upholding the order's validity, the Wisconsin Supreme Court concluded:


  • That the order was issued by a neutral, detached magistrate.
  • That the affidavit provided by Madison police provided probable cause for the portion of the order authorizing the installation, monitoring and removal of the GPS tracker.
  • That portions of the order authorizing Madison police to search any buildings or structures containing Sveum's car were arguably invalid because the affidavit did not demonstrate probable cause for those searches.  The Court severed those portions of the order, noting that police did not search those areas.
  • That the order described with sufficient particularity the justification offered for the GPS tracker placement and the manner in which police would place the tracker
  • That Madison police reasonably executed the order and reasonably obtained  the data from the GPS tracker.


Records from the Wisconsin Department of Corrections indicate that Michael A. Sveum remains incarcerated at the Oshkosh Correctional Institution in Oshkosh, Wisconsin.


The Wisconsin Supreme Court's decision in State of Wisconsin v. Michael A. Sveum, No. 2008AP658-CR, appears at the Court's website:


The Dane County District Attorney's Office prosecuted Sveum in Dane County Circuit Court.  Assistant Attorney General Daniel J. O'Brien represented the State of Wisconsin in the Wisconsin Supreme Court.