As party central USA, Clark County attracts more than its share of people doing illegal drugs.
As a result, Las Vegas police, who oversee the entire county, arrest and charge thousands with drug possession or trafficking. By 1990, police averaged 4,000 drug arrests per year.
But a new report by ProPublica, a non-profit investigative newsroom, is casting big doubts on the color-changing field tests that police use to identify a drug.
And according to the story published in the Las Vegas Review-Journal, police here have long known the tests were unreliable but kept using them anyway.
The story by Ryan Gabrielson also questioned the Clark County Public Defender's Office for not challenging the tests in court. Gabrielson said the Clark County District Attorney, Steve Wolfson, would not talk to him for the story.
Ryan Gabrielson, reporter, ProPublica