Oklahoma Judge Tosses Licence Plate Camera Evidence, Citing Supreme Court Digital Privacy Ruling

A federal judge in Oklahoma has thrown out evidence in a meth trafficking case after finding that an officer's search of automatic licence plate recognition (ALPR) data was unconstitutional. Judge Sara Hill ruled on October 1 that a deputy improperly used data from Flock cameras to build a case against Melisa Kyle. Experts describe it as the most significant example so far of how a recent Supreme Court decision on geofencing, known as Chatrie, will affect digital evidence and Fourth Amendment proceedings.

In Chatrie, a majority of justices found that police searches of historical cell phone locations provided by third-party tech companies are limited by the Fourth Amendment. Judge Hill cited that June decision repeatedly. She described Flock searches as "approaching dragnet-type law enforcement practice" that can be unconstitutional without a warrant. According to her ruling, the deputy stopped Kyle primarily because she had a California plate, then used Flock to find 50 instances of her car travelling across multiple states over a month. Hill called this an "unconstitutional warrantless search" and an example of "indiscriminate mass surveillance". The evidence from the later search of her vehicle was ruled inadmissible.

The decision does not set a binding precedent. However, it breaks from a consistent pattern of courts accepting warrantless ALPR searches because they do not track a person's every movement minute by minute. Experts say it will likely influence judges in future cases involving ALPR data.