A minor argument escalated into one participant pulling a gun and killing an acquaintance for what the prosecutor said was no apparent reason.

“Seven times. That’s how many times the defendant shot Brandon Luster,” Deputy Pima County Attorney Julie Sottosanti said.

Donald Earl Woods is on trial for first-degree murder and possession of a deadly weapon by a prohibited possessor in connection with the shooting death of Luster on Oct. 16. Woods previously served 12 years in prison for armed robbery and sexual assaults.

Luster was shot in the parking lot of an apartment complex on North Fontana Avenue near East Grant Road.

In opening statements before Pima County Superior Court Judge Christopher Browning, Sottosanti said Luster’s girlfriend had been involved in a dispute with a friend of Woods earlier on the night of the shooting.

After spending part of the night partying, Luster and the woman returned to the apartment to speak Woods.

“Brandon didn’t have a gun on him; they hadn’t even had a fistfight,” Sottosanti said. “The defendant just started shooting.”

Sottosanti said witnesses told police they heard the defendant shouting, “I’m Dirty Red,” his nickname, while he shot the victim.

Defense attorney Amanda Bynum said the contradictory eyewitness accounts of the crime and 911 calls would show that Woods didn’t shoot the victim. She disputed the contention Woods called out his own name during the shooting.

Bynum told jurors that rather than instigate a fight, Woods was trying to stop an escalating dispute between Luster’s girlfriend and his own friend, who was living with him at the apartment.

The trial continues today in Pima County Superior Court.

Contact reporter Patrick McNamara at 573-4241 or pmcnamara@tucson.com. On Twitter @pm929.