DALLAS (AP) - The Latest on the death of a man who testified at the murder trial of Dallas police officer Amber Guyger (all times local):

3:05 p.m.

An attorney for the family of a man who was shot to death days after testifying at the murder trial of a former Dallas police officer is calling for an outside investigation into his killing.

Attorney Lee Merritt, who represents the family of Joshua Brown, says "a cloud of suspicion" sits over the death of Brown, who was fatally shot on Friday, two days after jurors sentenced former officer Amber Guyger to 10 years in prison for killing her neighbor.

Police said Tuesday that three Louisiana men are suspected of killing Brown during a drug deal, and that his death had nothing to do with the Guyger case.

But Merritt said afterward that an agency other the Dallas Police Department should investigate Brown's death so the findings will be viewed as "authentic and reliable."

1:20 p.m.

Dallas police say three men are suspected in the killing of a man who testified at the trial of a Dallas police officer who killed her upstairs neighbor.

Assistant Chief Avery Moore said at a news conference Tuesday that the three men from Alexandria, Louisiana, will face capital murder charges in last Friday's killing of Joshua Brown.

Moore says the three were in Dallas to buy drugs from Brown, who was fatally shot at a Dallas apartment complex. He says the killing was not tied in any way to Brown testifying at the murder trial of former officer Amber Guyger, who was sentenced last Wednesday to 10 years in prison for killing her neighbor, Botham Jean.

Brown lived on the same floor as Jean and testified about what he heard the night Guyger killed him.

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