Less than a week after Guy McEwen was a reluctant witness in a murder trial, he was killed in a barrage of bullets as he ran down a New Orleans street.

Assistant Police Superintendent Marlon Defillo declined to speculate Friday if the Thursday night murder was linked to McEwen's appearance as a witness for the prosecution in the murder trial of David Bonds. Bonds was acquitted last week in the death of Dinerral Shavers, a drummer for the Hot 8 Brass Band who also taught high school band.

Defillo said police were investigating several possible motives in the death of McEwen, 20, who died after killers opened fire with at least two guns.

"His character was certainly highly questionable," Defillo said of McEwen, who was arrested in March for possession of crack cocaine.

McEwen was one of the people in the car with Shavers when Shavers was shot in the head in December 2006. Police have said Shavers was the victim of a stray bullet meant for his teenage stepson, the result of a neighborhood feud.

At Bonds' trial, McEwen testified but said he could not identify the shooter. Three teenage girls were also among the witnesses — all reluctant to appear. Only one identified Bonds, 18, as the man she saw shoot at the car.

During the trial, one juror was dismissed after he told the judge that he believed he'd seen Bonds make a gun-like hand signal at witnesses. A spokesman for the district attorney confirmed that, after the juror made the allegation, the judge granted a defense motion to remove the juror and replace him with an alternate. The jury eventually reached an 11-1 verdict for acquittal.

Shavers' death in late December 2006 and the still-unsolved slaying days later of independent film maker Helen Hill spurred a January 2007 march on City Hall that drew an estimated 5,000 people demanding that the city do more about crime in the wake of Hurricane Katrina.

Prosecutors had trouble securing testimony from the beginning and prosecutors at one point dropped the case, sparking more public outrage.

Defillo said Friday that witness cooperation is improving in New Orleans since the police and district attorney's office have begun working more closely. However, he acknowledged that the problem of witness intimidation persists.

"It's not unique to New Orleans," said criminologist Peter Scharf. "There is a mentality of don't snitch, don't cooperate. Certainly fear of retaliation is part of it, and an incident like this will have a chilling affect if it's determined to be for that reason."