Secrecy around police surveillance equipment proves a case’s undoing

The case against Tadrae McKenzie looked like an easy win for prosecutors. He and two buddies robbed a small-time pot dealer of $130 worth of weed using BB guns. Under Florida law, that was robbery with a deadly weapon, with a sentence of at least four years in prison. But before trial, his defense team detected investigators’ use of a secret surveillance tool, one that raises significant privacy concerns. In an unprecedented move, a state judge ordered the police to show the device -- a cell-tower simulator sometimes called a StingRay -- to the attorneys. Rather than show the equipment, the state offered McKenzie a plea bargain.

McKenzie’s case is emblematic of the growing, but hidden, use by local law enforcement of a sophisticated surveillance technology borrowed from the national security world. It shows how a gag order imposed by the FBI -- on grounds that discussing the device’s operation would compromise its effectiveness -- has left judges, the public and criminal defendants in the dark on how the tool works. That secrecy, in turn, has hindered debate over whether the StingRay’s use respects Americans’ civil liberties. “It’s a terrible violation of our constitutional rights,” asserted Elaine Harper, McKenzie’s grandmother, who raised the young man. “People need to know -- the public needs to know -- what’s going on.”