A member of a notorious Boston street gang who allegedly shot one man to death and seriously wounded another four years ago was issuing a “deadly and permanent lesson that you do not go against fellow Lucerne Street Doggz,” a Suffolk County prosecutor told Superior Court jurors in an opening statement.

The trial of JAMES A. WALKER, a.k.a. “GUNNA” (D.O.B. 9/9/86), of Dorchester began today, with the defendant facing charges of first-degree murder for the homicide of 20-year-old Antoine “Pun” Perkins, armed assault with intent to murder and assault and battery with a dangerous weapon for the non-fatal shooting of Perkins’ friend, then 19, and unlawful possession of a firearm for the July 22, 2006, incident on Morton Street.

Assistant District Attorney Edward Krippendorf told the court that, a month prior to the shooting, Perkins had arranged for some of his Lucerne Street Doggz associates to purchase two pounds of marijuana from a third party. Instead of making a purchase, those friends stole the drugs and left the area, Krippendorf said.

The third party contacted her boyfriend, who confronted Perkins about the theft.

“When he put it to Antoine Perkins about what had just happened, Antoine Perkins took the only route he knew, which was to bring [the third party] to his friends, to the place where he might find the people who just did this,” Krippendorf said.

Perkins brought the third party’s boyfriend and a few of that man’s associates to Walker’s Talbot Avenue home. When Walker encountered the group, Krippendorf said, he labeled Perkins a “snitch”.

“He was not happy with Antoine Perkins bringing these individuals over to his house,” Krippendorf said.

Walker went into his home and came out with a gun, Krippendorf told the court, and a “gun battle” broke out between Walker and his associates and the men who had accompanied Perkins to the house. Nobody was hurt, he said, and the two parties scattered.

“From that point forward, you’ll hear that this man, James Walker, was angry with Antoine Perkins for bringing these people up to his house and going out against fellow Lucerne Street Doggz gang members,” Krippendorf said.

On July 22, Walker and a few of his associates went to visit the gravesite of a friend who had been killed a year earlier. Later that same evening at about 11:45 p.m., Walker and a few of his associates walked down Morton Street, where Perkins lived, Krippendorf said.

“You will hear that James Walker was that lone gunman that approached the front steps, approached the front gate area, raised the gun and fired at Antoine Perkins.”

Krippendorf told the court that a witness who had seen the victim just moments before the shooting turned around when he heard the gunshots and saw a person jump a nearby fence and then turn to look right at him.

“And the person who turns and looks right at him is the person who is sitting here at this table, James Walker,” Krippendorf told the court. “A person who [the witness] knew at that time, who he had seen over the course of the past few weeks before that, and who…he had conversations with and recognized as ‘Gunna’ – which you will hear is the defendant’s nickname.”

Perkins was struck in the head and his friend was struck in the neck. Boston Police officers and emergency medical personnel arrived on the scene and transported the victims to Boston Medical Center. Although Perkins’s friend survived, Perkins succumbed to his injuries shortly thereafter.

Krippendorf told jurors that by the end of the trial, “you will know beyond a reasonable doubt who it was that went down to Morton Street that night and shot Antoine Perkins. You will know that it was this man, James Walker.”

Katherine Moran is the DA’s assigned victim-witness advocate. Walker is represented by attorney James Budreau. Judge Raymond Brassard is presiding in courtroom 815 of the Suffolk Superior Court.