In an extremely rare verdict, a federal jury in Chicago on Monday convicted a city police officer of violating civil rights by using excessive force in a Dec. 22, 2013, shooting that wounded two teenagers.

Marco Proano is the first Chicago police officer in at least 15 years to face federal criminal charges for a shooting while on duty.

Proano fired 16 shots into a stolen car full of black teens as the car reversed away from police who had stopped them for speeding.

Proano and his partner were backing up officers who had stopped the car. Dashcam video shows Proano drawing his weapon immediately after getting out of his car, holding the gun sideways and pointing it at the car. He starts firing as the car goes into reverse to try to get away from the officers, and he keeps shooting even after the car hits a light pole, until he empties his magazine.

The Associated Press reports:

"The prosecution relied on dashcam video of the incident, playing it several times for jurors during the weeklong trial in U.S. District Court in Chicago." 'He pulled his gun out, held it to one side and aimed it at those kids to send a message and to show who was in charge,' [Assistant U.S. Attorney] Erika Csicsila said. ..."Defense lawyer Daniel Herbert said his client was faced with a 'split second' decision, influenced by the fact that he was in a high-crime area and that another officer had allegedly mentioned a gun; it was a BB gun that had fallen out of the car."

One of the car's occupants was injured in the hip and heel and the other in the shoulder.

A federal jury deliberated for about four hours Monday before finding Proano guilty of two counts of using excessive force in violation of the victims' civil rights.

Chicago acting U.S. Attorney Joel Levin says, "Police have a very difficult job to do and the overwhelming majority of police officers are doing it right. And they are respecting the constitutional rights of citizens. But when an officer violates those rights, we, federal prosecutors take it seriously, we will investigate it and we will prosecute it to the full extent of the law."

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