One of the downsides of all of the new gee-whiz identification technology law enforcement is adopting (usually with hefty federal subsidies) is that it never works quite as well as advertised. The FBI touts facial recognition software as the bad guy-tagging tool of the future, but you have to dig through documents to discover that the feds consider a false positive rate of 20 percent to be perfectly acceptable.

We don't really know what the false positive rate for license plate scanners is, but we do know it has one. At least, Mark Molner, a Prairie Village, Kansas, attorney knows it, because a scanner misread his BMW's license plate for that of a stolen Oldsmobile plate, and the next thing he knew, cops with guns in hand had him surrounded and wanted to know his business.

Writes Jay Senter at the Prairie Village Post:

Mark Molner, whose law office is just north of the intersection of 75th Street and State Line Road, was driving back from a sonographer's appointment with his wife around 5:15 p.m. Monday when a Prairie Village police car pulled up behind him. "As there were tons of cars around me, I was not certain who they were pulling over, but as I had been at the light some time, I did not think that I had had the opportunity to do anything to interest the officers, so when traffic permitted, I pulled forward with it, slowly," Molner said. "At that time, the cruiser darted in front of me and attempted to pin me by parking diagonally across both lanes of traffic, and the motorcycle took up a place directly behind me." As one of the officers approached Molner's car, Molner noticed that he had his gun out. "He did not point it at me, but it was definitely out of the holster," he said. "I am guessing that he saw the shock and horror on my face, and realized that I was unlikely to make (more of) a scene." After a few moments of conferring with the other officer on the scene, the policeman returned to Molner's window and told him that a license plate scanner mounted on his police unit had thrown off an alert that Molner was in a stolen vehicle. As it turned out, though, the license scanner mounted on the car had misread a "7" on Molner's license plate as a "2." The alert the officer received was related to a stolen Oldsmobile. Molner was driving a black BMW. Molner's wife, who is four months pregnant, watched the incident unfolding from her car in the parking lot of Molner's office.

Since Molner's wife wasn't beaten and no dogs were killed, this incident marked an unusual exercise of restraint by the police officers. The attorney, though, wants to know why officers had their guns drawn, given that they weren't sure they had the right car or guy—and didn't as it turned out.

Which is another downside of all of the new gee-whiz identification technology law enforcement is adopting. It inevitably means more encounters between police and the public. Given law enforcement's increasingly militarized approach to the world, that usually involves an inclination to poke a boot or a bullet into somebody and then ask questions later.

Which is always a problem, but especially when your gee whiz techology screams "j'accuse" at the wrong damned person a large percentage of the time.