DALLAS (CBSDFW.COM/CNN) – His testimony was seen around the world and now citizens want to see an arrest for his murder. Joshua Brown, a witness for the prosecution in the Amber Guyger murder trial, was gunned down last Friday at an apartment complex not far from where Botham Jean was shot and killed in his own home.

But almost a year before testifying in the Guyger trial, Brown was wounded in a shooting outside Dallas Cabaret South, a strip club off Interstate-35, that left another man dead.

Brown believed he was the target in the November 23 strip club shooting and felt there were “still people out there who wanted to do him harm,” according to attorney Lee Merritt, who represents Brown’s family.

The killing happened just 10 days after Brown testified in the Guyger case. So far, no one has been arrested for his murder.

Now, a mystery now surrounds the death of Brown, a relatively unknown 28-year-old who reluctantly took the stand.

Merritt has called for an independent investigation into the killing, acknowledging that speculation has begun to spread. He said it “doesn’t mean there’s evidence” of police involvement or connection to the Guyger case.

“This case must be resolved, and that investigation that leads to finding the person must be seen as trustworthy or transparent by the community,” Merritt said Monday on CNN.

Deadly shooting outside Dallas Cabaret (credit: Robert Flagg/CBS 11 News)

Nicholas Shaquan Diggs is the victim who was killed in the 2018 shooting that left Brown wounded. Citing an affidavit, the Dallas Morning News reported that a man had waited for Brown outside the club and the two fought. The man allegedly started shooting when Brown tried to leave.

Diggs’ brother, Bruce, told CBS 11 News that Brown was the intended target that early morning and his brother “was actually trying to break up the fight” when he was shot and killed.

“Members of Joshua’s family have expressed to me, and his close friends, that there were ongoing threats related to the November 2018 shooting at the Dallas Cabaret,” Merritt said.

Kendall Morris, 26, was indicted in June for murder and aggravated assault with a deadly weapon, court records show. He pleaded not guilty and is out on bond, his attorney, Henry Campbell, told CNN. Another suspect or person of interest in the shooting was never arrested.

Campbell said Morris had “nothing to do with what happened to Josh,” and that his client had “no reason to want to retaliate” because he is innocent of the November shooting.

Brown was expected to testify in the upcoming murder trial.

According to Merritt, Brown tried to keep “a low profile intentionally until some of the heat” from the strip club shooting died down. He moved out of the South Side Flats apartment complex where he, Guyger and Jean had all lived.

Merritt said Brown was subpoenaed to testify in Guyger’s trial, but “made it clear he had no interest in testifying in open court in that trial.”

“I think he had some apprehension about being seen as an informant or a snitch,” Merritt said.

Merritt said Brown’s mother knew her son was “really bothered by the fact that he was given a lot of exposure from the trial, a lot of unwanted attention.”

The attorney said a threatening post appeared on Brown’s social media on the very day of his testimony in the Guyger trial.

“Someone wrote on his wall ‘now we know where you are.’ They later deleted that post,” Merritt said.

Dallas police said they are investigating Brown’s death.

Anyone with information about his murder is asked to contact Dallas police at 214-671-3690 or email jacob.white@dallascityhall.com. Crime Stoppers is also offering up to $5,000 for information leading to an arrest and indictment in the case. Anonymous tips can be left on the hotline at 214-373-8477.