Investigators said several fights broke out just before two men opened fire.
The woman killed was 26-year-old Clara Myhung Hee Chun of San Gabriel. The three wounded men, all between the ages of 18 to 30, were taken to a local hospital, one of them critically, officials said.
"Several partygoers had been involved in an altercation at some point in the evening and subsequent to that there was a shooting involving a couple of males," said Lt. Patrick Nelson of the Los Angeles County Sheriff's Department. "We don't have a better description yet, but detectives are in the process of interviewing additional witnesses."
On Saturday afternoon, investigators had dogs sniffing through the bushes trying to pick up a scent of the shooters involved.
Anyone with information on the two shooters is asked to call the sheriff's homicide bureau at (323) 890-5500.