A man charged with two murders will likely head to prison on the basis of a highly reliable witness’s testimony. But the witness isn’t a person; it’s a GPS unit that was mounted on his vehicle. According to the prosecution’s argument, the tracker clearly shows that the defendant was present at the location of the murders at the time that they occurred.
The most that GPS readings can prove is the location of the murder suspect’s car during the time it was tracked. As the prosecuting attorney displayed in court, the Garmin GPS unit mounted on the suspect’s car reported its geographical location almost 10,000 times within the space of a week. When those locations were added to a map, they showed the car driving past the house where the murder happened numerous times in the days leading up to the event.
Even more importantly, the data placed the car at the house for several hours at midday on the day of the murders. Later reports also track the car traveling to the storage facility where police recovered the murder weapon and other evidence related to the crime. As expected, the defending lawyer raised objections to the use of the GPS unit as evidence. He claimed that the readings should not be considered reliable since the unit itself had not been inspected by an expert and ruled trustworthy. In addition, he suggested that looking at the unit’s readings in the first place was an illegal search, not validated by a court-ordered warrant.
The judge, however, did not appear to take these objections too seriously, and decided to admit the readings as valid evidence. As long as the jury is willing to grant that the presence of the suspect’s car at a certain location implies the suspect’s presence, their decision seems clear.
The U.S. Supreme Court recently ruled that police may not secretly plant a GPS tracker on a suspect’s vehicle without a warrant. This case, however, is different in that the tracker was already on the vehicle. Also, the police came in contact with it and inspected its readings only after the suspect had been arrested. One can only imagine this defendant’s frustration at having recorded his own movements during the course of the crime.Google+