IN 2013, 18-YEAR-OLD Tadrae McKenzie robbed a marijuana dealer for $130 worth of pot at a Taco Bell in Tallahassee, Florida. He and two friends had used BB guns to carry out the crime, which under Florida law constitutes robbery with a deadly weapon. McKenzie braced himself to serve the minimum four years in prison.
But in the end, a state judge offered McKenzie a startlingly lenient plea deal: He was ordered to serve only six months’ probation, after pleading guilty to a second-degree misdemeanor. The remarkable deal was related to evidence McKenzie’s defense team uncovered before the trial: Law enforcement had used a secret surveillance tool often called Stingray to investigate his case.