(STMW) — The man charged with killing Chicago Police Officer Thor Soderberg in 2010 was “filled with hatred” when he coldly fired three shots into the 11-year veteran with the officer’s service weapon, a prosecutor said Monday.

On the opening day of the murder trial for Bryant Brewer, Cook County Assistant State’s Attorney Brian Sexton said Brewer hopped a fence outside a police station at 61st and Racine because he was “looking for the police,” the Chicago Sun-Times is reporting.

Bryant Brewer | Chicago Police

Bryant Brewer | Chicago Police

Witnesses had heard Brewer mumbling “f— the police” and “shoot the police” as he walked toward the station in the afternoon of July 7, 2010, Sexton said in an opening statement before Cook County Judge Timothy Joyce.

After a fight outside Soderberg’s car, Brewer grabbed the officer’s 9mm handgun and fired into his back, his right eye and the top of his head, Sexton said. Then he allegedly fired at a janitor and a police officer who was checking out what was happening, but he missed both of them.

“He is proud he gunned down a police officer,” Sexton said, as Soderberg’s widow and his fellow officers listened in court.

“He is a police officer’s worst nightmare.”

But Caroline Glennon, one of Brewer’s defense attorneys, said her client feared for his life when he shot the 43-year-old Soderberg, who had just finished his shift and was changing out of his uniform outside his yellow Subaru as he prepared for a volleyball game.

Glennon, an assistant public defender, said Soderberg brutally pistol-whipped Brewer when he came over a chain-link fence around the parking lot behind the station, which housed the Targeted Response Unit and was formerly the Englewood police district station.

Brewer was suffering from a brain injury from the blows to his head when he grabbed Soderberg’s gun and shot him, Glennon said. Brewer thought the officer was going to pick up his gun and kill him, she said.

Bruises on Soderberg’s knuckles and Brewer’s DNA under Soderberg’s fingernails show they were in a vicious brawl before the shooting, Glennon said. There was also gunshot residue on both of the officer’s hands, indicating they were struggling over the gun, she said.

Glennon said Brewer was later diagnosed with head trauma that explains his irrational actions with the gun after he killed the officer.

Soderberg was one of six officers killed in 2010, the deadliest year for the department in decades.

Brewer’s bench trial is expected to last more than a week. He faces natural life in prison if convicted of first-degree murder of an officer.

Brewer, 29, periodically nodded his head and seemed to talk to himself during opening statements Monday. His attorneys are expected to present evidence that he was insane at the time of the killing.

Tests also showed drugs including PCP, opiates and marijuana were in Brewer’s system at the time of the shooting.

Sexton said Brewer was not insane but is simply a sociopath.

“He does not like authority,” Sexton said.

Soderberg was an instructor at the Chicago police academy.

But on the day he died, he and a partner from the academy were working in Operation Protect Youth on the South Side, Sexton said. The program helped shepherd students to and from school in dangerous neighborhoods, he said.

Soderberg’s wife, Jennifer Loudon, took the witness stand at the Leighton Criminal Court Building. She calmly testified about her last conversation with him, as he was headed to work.

“I told him to have fun and stay safe — and I loved him,” she said.

His partner, Detective Phil Visor, said he dropped off Soderberg at his Subaru and said, “I’ll see you tomorrow.” Visor returned to patrol but rushed back to the station when he saw police cars were heading that way with their lights and sirens on.

“I walked over myself and saw him,” Visor testified, saying Soderberg’s body was slumped on a fence between two cars.

Brewer’s attorneys emphasized there’s a gap in the video from one of the surveillance cameras pointed toward Soderberg’s car in the parking lot.

No video shows the shooting taking place and no witnesses saw it, the defense attorneys say. And some footage is missing, they say.

But Sexton said a combination of witness statements, video and other evidence will prove that Brewer was guilty of first-degree murder.

“This is not a whodunit,” he said. “This is a he done it.”

(Source: Sun-Times Media Wire © Chicago Sun-Times 2015. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)