Police arrested 13 people Sept. 11 and the following days in connection with the killing of Trevon Richardson in the 2100 block of Crestview Lane on July 14. A second male victim was wounded in the shooting, which involved suspects firing multiple shots into a moving vehicle.
Investigators said they've since "determined that the violent criminal street gang Midtown was responsible for the homicide."
One suspect is still at large: 19-year-old Pittsburg resident Amen Allen. Police said he should be considered armed and dangerous.
Of the initial nine people arrested, seven adults and two juveniles have been charged by the Contra Costa County District Attorney's Office with murder and are currently in custody awaiting court proceedings. Police said other charges include alleged conspiracy to commit murder, accessory to murder, firearms violations, narcotics-related offenses, and other alleged offenses.
Anyone who sees or has information about Allen can contact Det. Gutierrez at (925) 252-4095 or the Pittsburg Police Department's tip line at (925) 252-4040.