OAKLAND -- Michael Peau and Roberto Guzman Jr. were pretty good friends until early September 2011 when Peau sold the father of Guzman's girlfriend a car, a prosecutor said Wednesday.

Turns out, the car was stolen, taken during a carjacking weeks before and the father of Guzman's girlfriend, Gerardio Vasquez, was almost arrested when he tried to have it registered, deputy district attorney Luis Marin said.

Vasquez was angry at Peau, who he treated as family, but not mad enough to tell police who he purchased the car from. Vasquez also did not demand the $100 back that he gave Peau for the car; he simply told the 23-year-old not to hang around the family for a while, Marin said.

Guzman was also angry at Peau for almost getting the man he considered his father-in-law arrested. In the days following the car sale, Guzman and Peau had heated exchanges with one tiff erupting after Guzman told Peau to leave and ending with Peau brandishing a gun.

On Sept. 24, 2011 at about noon, Peau used that gun to kill Guzman as the 20-year-old changed the oil in his car in front of the Vasquez home at 3288 Hannah Street in West Oakland.

Marin told a jury of seven men and five women Wednesday he will prove Peau murdered Guzman out of anger for being disrespected by the younger man. Peau fired 11 shots at Guzman, most of them coming as Guzman laid on the pavement in front of his car.

Guzman was hit with 10 bullets, six of which tore through his body and another two which entered his back and rested inside his body. Guzman died at the scene as he was being held by his girlfriend and mother of his child.

"It was all over disrespect; he didn't appreciate the way the victim talked to him several days before," Marin said of the killing. "Mr. Peau did not appreciate being told what to do."

Peau's attorney, David Bryden, said his client does not dispute most of the facts in the case but said the killing was done in self-defense as Guzman tried to attack Peau with a screwdriver.

"Mr. Peau did shoot but in panic," Bryden said. "He was trying to stop the advancing Mr. Guzman."

Bryden promised the jury that his client will testify in the case and said the story as described by Marin is not completely accurate. Bryden said it was Guzman who played the aggressor and that Peau simply went to the Vasquez house on Sept. 24, 2011 in hopes of resolving the dispute.