In 2003, Bryn Mawr college student Janet H. Lee was arrested in a Philadelphia airport for drug smuggling. Airport officials found several condoms that Lee had stuffed with flour for use as stress-busters during finals week. When two "field tests" showed the flour to be opium and/or cocaine, Lee was arrested, and held in prison for 21 days until lab tests later confirmed her story.
The good news is that Lee has won a $180,000 settlement for her wrongful imprisonment.
The bad news is, the settlement means we'll probably never know how or why two "field tests" would have ordinary household flour come back positive for opium and cocaine.
It isn't the first time these "field tests" conducted by police have turned up repeated false positives, leading to false arrests and wrongful imprisonment.