But a federal jury on Monday decided that the shooting — captured on a police dashboard camera video — wasn't the action of a cop but a criminal.
In an unprecedented verdict, the jury deliberated about four hours before convicting Proano of two felony counts of using excessive force in violating the victims' civil rights. He faces a maximum of 10 years in prison on each count but probably will get far less because he has no prior criminal history.
The 11-year Chicago police veteran, dressed in a dark gray suit and glasses, kept his hands clasped in front of him on the defense table and showed no emotion as the verdict was announced in U.S. District Judge Gary Feinerman's hushed courtroom.
Feinerman scheduled sentencing for Nov. 20. But federal prosecutors indicated that next week they will seek to detain Proano as a danger to the community.
Proano is the first Chicago police officer in memory to be convicted in federal court of criminal charges stemming from an on-duty shooting. He is Latino [that's why]. He also was the first officer to go to trial in any shooting case since the court-ordered release of the Laquan McDonald shooting video in November 2015 sparked protests, political turmoil and promises of systemic change from Mayor Rahm Emanuel.
Prosecutors said the dash-cam video of the shooting — which unfolded in about nine seconds — showed Proano violated all of the training he received at the Police Academy, including to never fire into a crowd, fire only if you can clearly see your target and stop shooting once the threat has been eliminated.
The video — played several times for jurors, including in slow motion — showed Proano walking quickly toward the stolen Toyota within seconds of arriving at the scene while he held his gun pointed sideways in his left hand. Proano can be seen backing away briefly as the car went in reverse, away from the officer. He then raised his gun with both hands and opened fire as he walked toward the car, continuing to fire even after the car had rolled into a light pole and stopped.
"Marco Proano drew first, shot next and then he tried to justify it later," Assistant U.S. Atty. Erika Csicsila said in her closing argument Monday. "He came out of his car like a cowboy. 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."
Last week, jurors heard testimony from two police training officers that cops are taught to shoot only as a last resort against a deadly threat and to reassess the danger every two or three shots before continuing to fire.
Herbert argued Monday that the officer did exactly as he was trained: to stop the threat and protect the life of one of the teens, who was hanging from the passenger window as the car reversed.
This year, a U.S. Department of Justice investigation found the Police Department's use-of-force training was woefully lacking, part of a systemic failure that led to the routine abuse of citizens' civil rights.
Proano's quick conviction on the federal criminal charges was in stark contrast to how recent police misconduct cases have played out in Cook County criminal courts, where officers often elect bench trials instead of jury trials.
In the highest-profile case, former Det. Dante Servin was cleared in April 2015 by Cook County Judge Dennis Porter of involuntary manslaughter in the fatal, off-duty shooting of 22-year-old Rekia Boyd on the West Side. The judge's ruling all but said that prosecutors should have charged him with murder, not the lesser charge.
Also in 2015, Cook County Judge Diane Gordon Cannon acquitted then-Cmdr. Glenn Evans on charges he shoved his gun down Rickey Williams' throat and threatened to kill him while on duty. In throwing out all charges, Cannon belittled evidence of Williams' DNA on Evans' service weapon as "of fleeting relevance or significance."
This year, Cook County Judge James Linn acquitted Officer John Gorman of all charges stemming from an off-duty incident in which he was accused of firing shots at a vehicle during a traffic altercation after he'd been drinking.
On Monday, speaking to reporters after the verdict, acting U.S. Atty. Joel Levin acknowledged that without video evidence, it's extremely difficult to prove beyond a reasonable doubt that an officer knew he was using excessive force when he opened fire.
"Historically, the lack of videos has made it difficult for us to meet our burden," Levin said in the lobby of the Dirksen U.S. Courthouse. "With the availability of more videos ... it can, as it did in this case, supply the evidence we need to make the case."
Proano left the courthouse without comment, ignoring shouted questions from reporters as he ducked into a SUV. His lawyer, Daniel Herbert, also declined to comment.
Meanwhile, the Fraternal Order of Police, the union representing rank-and-file officers, expressed disappointment at the verdict in a statement.
"The pressure on the police is making the job extremely difficult," the group’s president, Kevin Graham, said. "It seems that the criminal elements in our society are not accountable in our justice system, while the police face an intense scrutiny for every split-second decision they make."