Chicago has convicted its first criminal using facial recognition software, a new crime-fighting tool employed by police and prosecutors.

Pierre Martin was found guilty and sentenced to 22 years in prison for two armed robberies carried out last year on subway trains.

Chicago police identified Martin as the culprit after employing NeoFace, the city’s facial recognition technology. The system, created by NEC, allows officers to compare still photos with those stored in a database containing millions of mug shots.

Chicago Transit Authority surveillance cameras had recorded Martin in the act of using a gun to threaten subway riders in order to steal their cell phones. Using NeoFace, law enforcement compared the image of Martin’s face to the police department’s database of nearly 5 million criminal booking photos. Martin, who was in the database due to an arrest record dating back at least eight years, was identified by the recognition system as the most likely match to the face captured in the surveillance footage. He was also later identified by witnesses in a photo line-up.

State attorney Anita Alvarez praised NeoFace, telling the Chicago Sun-Times: “This case is a great example that these high-tech tools are helping to enhance identification and lead us to defendants that might otherwise evade capture.”

Chicago Police commander Jonathan Lewin called Martin’s arrest using NeoFace, which cost the city $5.4 million, “our first success.”

Civil libertarians have not been as excited by the city’s employment of facial recognition technology, which began last year. Their concerns center around the potential for misuse by police who, they say, might utilize it for general spying on the public. The potential for such misuse is magnified by the fact that Chicago has more than 24,000 surveillance cameras tied in to the city’s computer network, according to the American Civil Liberties Union of Illinois.

Lewin insisted NeoFace is only for “active criminal cases with an unidentified criminal subject,” and that “there will absolutely be no random surveillance—and facial recognition—of subjects in the public way.”

-Noel Brinkerhoff, Danny Biederman

To Learn More:

Armed Robber, Identified by Facial Recognition Technology, Gets 22 Years (by Frank Main, Chicago Sun-Times)

A First: Armed Robber Convicted Based on Chicago’s Facial Recognition Technology (Homeland Security News Wire)

Facial Recognition Software Creeps Closer to Total Accuracy (by Noel Brinkerhoff, AllGov)

San Diego County Quietly Scanning Faces for Its Growing Surveillance Database(by Ken Broder, AllGov California)