Officers responded to a report of a shooting in the parking lot of 1090 Mi Casa Court, near Monument Boulevard, at about 8:20 p.m., Lt. Steve Dyer said.
A large family party was being held when two men got into an altercation and shots were fired, Dyer said.
When officers arrived, they found Ismael Garcia Ramirez, 25, suffering from a fatal gunshot wound to the upper body, according to Dyer.
Witnesses provided information that led officers to the identification of a suspect car that was seen fleeing the scene, Dyer said.
The car was found in the 1200 block of Monument Boulevard near Victory Lane. Officers contacted the suspect, 29-year-old Vincent Ochoa, of Concord, arrested him, and booked him on suspicion of first-degree homicide, Dyer said.
Anyone with information about the shooting is asked to call Concord police at (925) 603-5922 or anonymously to (925) 603-5836.