Two were reportedly killed at the scene and two were hospitalized in critical condition. They were later declared dead at the hospital.
Luis Jimenez, 26, Angel Jimenez, 25, and Anthony Jimenez, 24, and their 25-year-old cousin Martin Haro, all of Willowbrook, were found shot about 8:45 p.m. Friday on the backyard patio of a home in the 2100 block of Bliss Street, said sheriff's Lt. Victor Clay of the Century Station.
Witnesses saw a black SUV with two male Hispanics inside leave the area.
The shooting was under investigation.
If you have information related to the case, you're asked to call Los Angeles County Sheriff's homicide investigators at (323) 890-5500.
City News Service contributed to this report.