Carlos Arvizu
Carlos Arvizu. Courtesy GoFundMe

A third suspect has been arrested on suspicion of murder in connection with the shooting last month of a young man in a neighborhood just north of the U.S.-Mexico border, authorities reported Wednesday.

Adrian Mark Rodriquez, 18, was already in jail on an unrelated charge when he was re-booked Tuesday morning in the gunshot death of 20-year-old Carlos Arvizu on April 7, according to the San Diego Police Department.

Patrol officers responding to reports of gunfire about 10:30 p.m. that day found Arvizu in the 100 block of East Park Avenue in San Ysidro, suffering from a gunshot wound to his upper body, SDPD Lt. Steve Shebloski said.

Paramedics took Arvizu to a hospital, where he was pronounced dead shortly after arrival.

Investigators determined that the shooter opened fire on the victim from inside a vehicle that pulled up alongside Arvizu in a front of a home, Shebloski said.

Police have not released a suspected motive for the fatal shooting.

On May 10, Jacob Christopher Kozik, 18, was taken into custody in San Bernardino for allegedly taking park in the fatal shooting.

Two days later, 19-year-old Marcos Anthony Carbajal of Chula Vista was booked in the case, according to police.

Rodriquez was being held at San Diego Central Jail without bail pending arraignment, scheduled for Thursday afternoon.

GoFundMe campaign has been set up to raise $15,000 to help Arvizu’s family with expenses.

City News Service contributed to this article.