A Chicago Tribune analysis of three years of suburban police department data finds that less than half of alerts by dogs lead to the discovery of drugs or paraphernalia. And that rate drops to less than a third for Hispanic drivers:

Advocates agree that many dog-and-officer teams are poorly trained and prone to false alerts that lead to unjustified searches. Leading a dog around a car too many times or spending too long examining a vehicle, for example, can cause a dog to give a signal for drugs where there are none.

Civil rights advocates and Latino activists say the findings support complaints that police unfairly target Hispanic drivers for invasive and embarrassing roadside vehicle searches.

Adam Schwartz, an attorney for the American Civil Liberties Union of Illinois, said the innocent suffer from unjustified searches.

“We've seen a national outcry about being frisked and scanned at airports,” Schwartz said. "The experience of having police take your car apart for an hour is far more invasive and frightening and humiliating."

To read the entire front-page article in the Tribune, go here.