The police had used the device to monitor the movements of the suspect, Scott C. Weaver, for more than two months. But the court ordered the evidence gathered from the device suppressed and ordered a new trial for Mr. Weaver.This holding is interesting in light of United States v. Knotts, 460 U.S. 276 (1983). In that case, the Supreme Court held that the Fourth Amendment (under the United States Constitution) was not violated by the use of a "beeper" that revealed where contraband, driven around in public, was tracked. As the Knotts Court explained it, the use of the beeper did not constitute a search because "[a] person travelling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another." Id. at 281.
At first blush, the New York decision seems to afford broader criminal procedural rights than the federal Fourth Amendment, under Knotts, would require. However, in addition to some other factual differences, GPS devices are more intrusive than beepers in what they reveal. Thus, the New York high court noted that the issue was "unclear" based on federal law and "premise[d its] ruling on [New York's] State Constitution alone."
It will be interesting to see what happens if (or when) the Supreme Court takes up a similar issue. Of course, that question will have to wait for another day as the New York court's state law basis is independent of federal law, and adequate to sustain the judgment.