EvidenceProf has the story of how the planting of a GPS device raised questions as to seizures of evidence in the case of the "wooded rapist":
Tennessee authorities have apprehended Robert Jason Burdick, the man they suspect of being the "Wooded Rapist," who raped 13 women. The method of apprehending him, however, may jeopardize their case against him. The 38 year-old Burdick has been charged with four rapes and two attempted rapes and is suspected of committing 13 rapes between 1994 and 2008. Most of those crimes were committed in homes that were near wooded areas, leading to its perpetrator being dubbed the "Wooded Rapist."
Burdick first became a suspect in these crimes on April 28th after police received a report of a masked man in a subdivision and an officer saw Burdick walking through the neighborhood and getting into a Jeep. The officer questioned Burdick, but he refused a search of his vehicle. Subsequently, officers, who were conducting 24-hour surveillance of Burdick, placed a GPS tracking device on his Burdick's Jeep even though they did not have a warrant.
Using the device, the officers tracked Burdick for two days, during which they, inter alia, followed him to the restaurant Tee Gees, took silverware, a plate, and a cup he had used, and got samples of his DNA. Police Chief Ricky Watson has said that the DNA matched evidence discovered at the "Wooded Rapist" crime scenes.
According to Watson, police did not need a warrant to place the tracking device on Burdick's vehicle. He would not say when or where the GPS unit was hidden on the Jeep, but said he it was done in a public place. "It's absolutely legal to do it," Watson said. "You can't do it when it's on private property." Defense attorney David Raybin, however, countered this argument by saying that the police might have jeopardized their case by using the tracking device without a warrant, which could be construed as a violation of the Fourth Amendment. So, who is right?
The post goes on to answer the question. I'm curious to see how the use of GPS devices for all sex offenders in some states (like California) will cause 4th Amendment problems. If an offender is spotted near (but not in a school) on GPS monitoring, what can the government do? What if a child is missing and 4 offenders were in the vicinity of the child when the disappearance occurred? Since GPS monitoring is for life, do these persons have a perpetual loss of 4th Amendment rights? If not, could these GPS devices actually lead to the exclusion of evidence in future cases?