Ten-year-old Trina Persad died when a gang member aiming for rivals fired a shotgun in her direction, sending fragments of metal into her face and head even as a family friend tried to hurry her and two other young children out of a city playground, a Suffolk County prosecutor said today.

JOSEPH COUSIN (D.O.B. 8/9/84) is charged with first-degree murder, receiving a stolen motor vehicle, unlawful possession of a firearm, and unlawful possession of a sawed off shotgun, all in connection with Persad’s shooting on June 29, 2002, and her death at Boston Medical Center two days later.

“This didn’t happen in LA,” First Assistant District Attorney Josh Wall told the Suffolk Superior Court jury that today began hearing testimony in the case. “This didn’t happen in New York. This happened in Boston. This happened in a park near a children’s playground.”

Wall told jurors that the evidence would show a running feud between two gangs operating within the City of Boston. One gang was associated with the areas of Magnolia, Intervale and Columbia streets and was known as MIC. The other gang was associated with the areas of Brunswick, Creston, and Fayston streets and was known as the Big Head Boyz.

“Big Head Boyz versus MIC – that’s what this case is about,” Wall said. “One of the longest standing rivalries in this city, and one of the most violent rivalries in this city.”

Cousin was affiliated with MIC and once admitted as much to a Boston Police officer, Wall said, calling them his “family.”

Wall said that members of the Big Head Boyz had shot at members of MIC earlier and that, on the evening of June 29, Cousin and others were preparing to retaliate at a park the Big Head Boyz considered their turf.

It was at that park that 10-year-old Trina, her two younger siblings, and a family friend they called “Auntie” were spending the summer evening until the woman saw the occupants of a black car exchange words with some young men on the nearby basketball court. Sensing trouble, she decided to take the three children home.

“But she only has two hands,” Wall said. “She can’t take Trina by the hand the way she takes the others.”

The four were just about to leave the area when the car, which had left, circled around again.

“When the back window comes down, it’s not words that come out,” Wall said. “When the back window comes down, it’s a sawed-off shotgun. There’s a shotgun blast – a deafening blast …. Trina’s on one end of that shotgun, and who’s on the other end?

“Joseph Cousin,” Wall said, pointing at the defendant. “Right here.”

Wall said jurors could expect to hear not only from police investigators but also from members of both rival gangs – cooperating witnesses who were speaking despite the universal code against “snitching.”

One witness, the prosecutor said, would testify that Cousin and other MIC members drove to the park in a car stolen specifically for their “mission.” The other would testify that “when the window went down in the back seat, it was Joseph Cousin” who was aiming the shotgun.

In addition to that testimony, fingerprint evidence would link Cousin to the car, as would Cousin’s presence at the car back in MIC territory just minutes after the murder. Inside the car was a spent shotgun shell.

“You will know, ladies and gentlemen, based on the evidence and beyond a reasonable doubt, that the killer is in this courtroom,” Wall said. “The person who killed that little girl is seated right here – Joseph Cousin.”

Cousin is represented by attorney William White. Testimony is expected to last two to three weeks and is ongoing before Judge Nancy Staffier Holtz in courtroom 907 of Suffolk Superior Court.