A week after a Cook County civil jury found he was essentially justified in the shooting death of 19-year-old Quintonio LeGrier, Chicago police officer Robert Rialmo was back in court Monday — on trial for his role in a December 2017 bar fight.

Rialmo’s attorney, Joel Brodsky, didn’t deny that his client, who was off-duty at the time, had thrown a couple of “jabs” in the early morning hours of Dec. 17, 2017, at Moretti’s Ristorante and Pizzeria on the Northwest Side.

But Brodsky said Rialmo, 29, did so only after he feared for his safety from two patrons, one of whom had “attacked” him at the bar.

“This all happens in an instant,” Brodsky told Cook County Judge Daniel Gallagher, who is hearing the misdemeanor case in the courthouse at 5555 W. Grand. “… His idea was to end the aggression.”

But prosecutors say Rialmo’s punches — which left the two patrons laid out in the bar area of the restaurant — were unprovoked. One of the patrons was getting ready to leave and merely trying to find his jacket near where Rialmo was standing, said Cook County Assistant State’s Attorney Kathryn Sodetz.

“With both men lying on the ground helpless, the defendant left the bar,” Sodetz said.

Lynne Reyes, who was at the bar the night of the incident, testified that neither of the men who were punched appeared intoxicated. Reyes also said she never saw either man act aggressively toward Rialmo.

Those two men, Atmiya Patel and Brandon Stassen, both testified on Monday.

Both said that they took a train from their homes in the Northwest Suburbs to the Edison Park neighborhood. Once in the city, they stopped at two bars before going to Moretti’s. Both testified that they each had only two drinks before arriving at Moretti’s.

Patel said that, as he and Stassen were getting ready to leave, he went to look for his black-and-white checkered coat. That night, Rialmo was wearing a similar coat.

In video footage played before Gallagher, Patel said that he believed Rialmo’s jacket was actually his own, and when he picked it up, Rialmo accused Patel of trying to steal it from him.

The video was played frame-by-frame by both Brodsky and the prosecutors.

Patel could be seen yanking on the jacket as Rialmo grabbed the other end. A short time later, Rialmo shoved Patel and, as he was standing back up, Rialmo punched him in the left side of his jaw.

“As it got heated, I was thrown to the tables and I don’t remember much after that,” Patel testified.

Stassen was also punched and knocked unconscious for a short time. He testified that he was later diagnosed with a concussion.

The trial is expected to last through Tuesday.

Speaking to members of the news media and municipal employees outside the courtroom, Rialmo expressed frustration with the six months of court proceedings that he has faced since he was charged last January.

Rialmo still faces possible discipline from the Chicago Police Board for his fatal shooting of LeGrier and Bettie Jones in December 2015. Rialmo’s actions at the bar are also under investigation by the Civilian Office of Police Accountability, the city’s police oversight agency.