Los Angeles County Sheriff Robert Luna speaks at a press conference in front of the Civic Center in Monterey Park, California, the United States, Jan. 22, 2023. (Photo: Xinhua)

An 11th victim died from injuries on Monday after an elderly gunman's deadly rampage at a Los Angeles-area dance hall, California police said, as authorities were still searching for a motive behind one of the state's worst mass shootings.