Marco Proano wore the uniform of a Chicago Police officer four years ago, when he fired 16 times in nine seconds at a stolen Toyota Avalon full of teenagers.

But in that moment at 95th and LaSalle in December 2013, Proano was no cop, U.S. District Judge Gary Feinerman said Monday. He did not represent the “thin blue line.”

Rather, Feinerman said Proano became “the source of chaos and violence,” wounding two teens in an “unjustified” criminal act.

That judge handed Proano a stiff five-year prison sentence Monday, and he said it’s “troubling” that Proano still doesn’t seem to agree he committed a crime.

“What happened here was not a close call,” Feinerman said.

Proano, 42, is the only Chicago Police officer in recent history to face federal prison for an on-duty shooting, according to authorities. A jury took less than four hours last August to find him guilty of two civil rights violations stemming from a shooting caught on a police dashcam video.

Federal prosecutors say he “could have killed each and every” passenger in the car.

But Proano seemed to take credit Monday for protecting them, telling the judge “there’s a reason why all these teenagers went home that night.” He insists he pulled the trigger to protect a teen hanging out of the window of the car when it suddenly reversed.

His attorney, Daniel Herbert, has described Proano as a “scapegoat” who has been “sacrificed to the furor” amid a wave of anti-police sentiment.

Monday’s sentencing followed a week that saw prosecutors drop several criminal charges in state court in connection with alleged police misconduct — including what is believed to be the first mass exoneration in Cook County history.

Proano’s indictment also followed the public release of video depicting the fatal shooting of 17-year-old Laquan McDonald by Chicago Police Officer Jason Van Dyke.

Herbert also represents Van Dyke, who faces murder charges in state court.

“These are difficult times,” Herbert said after Proano’s sentencing hearing Monday.

“We recognize the fact that police officers’ split-second actions are going to be judged by individuals that have the luxury to look at it through a different lens.”

Chicago Fraternal Order of Police President Kevin Graham added that Proano “has paid a heavy price.”

While handing down the sentence, Feinerman said police are given the benefit of the doubt — it’s “baked into the law.” But he also said “there are times when an officer’s conduct goes so far beyond the pale that he or she must be held to account.”

The judge rejected the idea that Proano is a scapegoat. Acting U.S Attorney Joel Levin later called it “nonsense.”

“Today he was sentenced for his crimes,” Levin said. “No one else’s crimes. He’s not a scapegoat in any way, shape or form.”

A CPD spokesman confirmed Proano’s employment has been terminated. He is a married father of three born in Ecuador who spent about a decade as a Chicago cop, working primarily in the Roseland neighborhood.

When Proano arrived at 95th and LaSalle on Dec. 22, 2013, the driver of the car full of teens had fled. A BB gun later fell out of the car, and Proano watched as the car suddenly began to reverse, with one teen hanging out of a window. Another teen had lunged forward from the back seat, thrown the car into reverse and pushed the gas pedal with his hands.

No one was in the vehicle’s path.

Proano can be seen in a dashcam video stepping forward, holding his gun sideways. Seconds later, he steps backward as the car reverses into view. Proano then lifts his gun again with both hands, upright, and a flash can be seen as he appears to open fire.