Last week, my Post colleague Abby Phillip wrote about Joseph Ray Burrell, a Minnesota man who spent more than two months in jail because a police drug field test incorrectly identified a bag of vitamins in his car as amphetamines.

It isn’t the first time one of these field tests has caused a wrongful arrest. Or the second. Or the third. In fact, I’ve been compiling a running list of all the materials that one or more of these field tests has mistaken for drugs. It includes . . .

Why, it’s almost as if these field tests will say whatever law enforcement officers want them to.

Six years ago, the Marijuana Policy Project put out a study to demonstrate the high error rate in these tests and to draw attention to the fact that false positives can lead to wrongful arrests. It didn’t seem to do much good.