By Dana Kozlov

(CBS) – A Chicago police officer caught on camera firing his weapon into a car of unarmed teens was involved in a fatal shooting previously, CBS 2 has learned.

Now, relatives of the victim who died want to know why the officer was allowed to remain on the street.

CBS 2’s Dana Kozlov reports.

Dashcam video of Officer Marco Proano showed him opening fire into a car of unarmed black teenagers in 2013. A retired judge was so outraged by video that he released it after a case against Proano was tentatively settled.

Equally outraged was the family of Niko Husband.

“When I seen that video and heard it was his name, I shouted out, ‘The man is still on the street. He killed my son!’” Priscilla Price, Husband’s mother, says.

In 2011, the 19-year-old Husband was at a party on the 8000 block of South Ashland when police were called to the area. The family’s attorney, Don Shapiro, says husband had his arms around his girlfriend, and when he failed to let her go, as ordered, officers stunned him, threw him to the ground.

“One of the officers dropped his Taser, somebody yelled ‘Gun,’ and Marco Proano rushed in and shot Niko three times in the chest and killed him,” he says.

At the time, Chicago police said Husband was reaching for a gun, which they recovered. Shapiro disputes that.

“There is no DNA linking him to the gun. There are no fingerprints linking him to the gun. It is an untraceable weapon,” he says.

Husband’s family filed a wrongful-death lawsuit almost two years before the 2013 shooting and never knew about it or the subsequent federal lawsuit involving Proano.

“We thought Proano was a loose cannon before finding out about this other incident — now we know he’s a loose cannon,” Shapiro says.

City attorneys are representing Proano. They said they could not comment further.

But in court documents, Proano denies he acted willfully and wantonly and states the use of deadly force conformed with state law. Officials say he is currently on desk duty pending an investigation into the 2013 incident.