A key witness in the murder trial of former Dallas police officer Amber Guyger who was shot and killed Friday was also slated to testify in Botham Jean’s family’s civil case against the city, a lawyer for his family said Monday.

Joshua Brown, a neighbor of Guyger and Jean, the man she was convicted of killing late last year at the South Side Flats apartment complex, was gunned down at around 10:30 p.m Friday night, the Dallas Morning News reported. Police confirmed that a fatal shooting took place around that time in the same location, which was at a different apartment complex from where Guyger and Jean lived. Dallas County’s medical examiner and Kimberlee Leach, a spokeswoman for the Dallas County district attorney, confirmed the victim’s identify to The Daily Beast.

Lee Merritt, a civil-rights attorney who represents the Jean and Brown families, also identified the victim as Brown.

“To have a key witness suddenly be killed is suspicious. Was this related to the trial? There is no clear indication,” Merritt told CBS News on Monday.

Merritt said Monday that Brown believed someone was trying to hurt him after he survived a shooting near a Dallas strip club last November. The lawyer said Brown didn’t want to testify in Jean’s trial out of fear of retribution, but he was eventually subpoenaed to testify.

“He had been shot less than a year ago and someone near him was killed,” Merritt said, noting the shooter in that case is still at large. “Joshua was concerned that that person might try to come back and finish the job.”

Merritt added Brown moved out of South Side Flats about three months after Jean was killed in September 2018 and tried to keep a “low profile” working in roofing and property management.

“He did not want to testify in that trial,” he said.

Brown was also set to testify in a civil case brought by Jean’s family against the city of Dallas in connection with the killing. Merritt said he was slated to be one of the case’s first witnesses.

The Dallas County Medical Examiner’s Office declined to provide The Daily Beast any additional details, but added a completed autopsy report will not be available for at least 90 days. Merritt said in a Saturday night Facebook post Brown “was ambushed at his apartment complex as he got out of his car and (was) shot at close range.”

Jason Hermus, the assistant district attorney and lead prosecutor in the Guyger case, told the Morning News on Saturday that Brown “bravely came forward to testify when others wouldn't.”

“If we had more people like him, we would have a better world,” Hermus was quoted as saying.

Police said several witnesses reported seeing a silver, four-door sedan fleeing the parking lot at a high speed after the shooting. Brown was reportedly found with multiple gunshot wounds.

He was taken to Parkland Memorial Hospital, but he died from his injuries. The Dallas Police Department declined to provide The Daily Beast with details on the investigation Monday or whether there’s any connection between Brown’s death and his testimony in Guyger’s trial last week. No suspects have been named in the case at this time.

Brown was a key witness for the prosecution in Guyger’s trial. Guyger, a white off-duty cop in uniform on the night of the killing, was found guilty of murder for fatally shooting Jean, an unarmed black man, in his own apartment. Guyger said she confused Jean’s apartment for her own and believed he was an intruder, shooting at him in self-defense.

“I thought it was my apartment,” Guyger told dispatchers 19 times on the 911 call played in court. “I thought it was my apartment. I’m fucked. Oh my God. I’m sorry.”

Guyger, 31, was sentenced to 10 years in prison on Wednesday. She faced as much as 99 years for the fatal shooting.

Brown lived across the hall from 26-year-old Jean, and testified that on the night of Sept. 6, 2018, he was in the hallway on the fourth floor of the apartment building when he heard what he thought sounded like “two people meeting by surprise.” He said at the trial that he couldn’t hear what they were saying before he heard two gunshots.

Merritt said Brown’s murder “underscores the reality of the black experience in America.”

“Brown deserves the same justice he sought to ensure the Jean family,” Merritt wrote on Facebook . “The Dallas County criminal justice system must mobilized to identify his killer and see that he is held accountable for this murder.”