[PowderMonkey]

"My advice to YOU if YOU’RE ever involved in a shooting: request to be taken to a hospital to have a blood sample and toxicology screen taken."

Sometimes even guys like Massad get in over their depth. Sorry, but that's the worst advice ever. There's a reason drug testing isn't universally conducted or required for law enforcement officers: false positive results. One false positive, though later corrected by follow-on testing for verification, is a major problem you don't need at a time like that. Early in my career, then AG Edwin Meese commanded that everybody in my particular outfit would set the tone of his administration's "zero tolerance" policy and "volunteer" to fearlessly undergo drug testing to prove its effectiveness. Fortunately, our fearless Chief told Meese, "you pee in the cup first, Sir." Meese blinked. We won. If it ain't broke, don't fix it.

[saleman]

“There’s a reason drug testing isn’t universally conducted or required for law enforcement officers: false positive results”

Maybe you could tell that to the judges who convict people all the time because of drug tests. Or, folks who are convicted for DUI. Or the folks who get probation revoked because of drug tests etc...