Two people pause at a memorial outside the Star Ballroom Dance Studio on Monday, Jan. 23, 2023, in Monterey Park, Calif. A gunman killed multiple people at the ballroom dance studio late Saturday amid Lunar New Year's celebrations in the predominantly Asian American community. (AP Photo/Ashley Landis)
MONTEREY PARK, Calif. (AP) — Investigators searching for a motive Monday in the worst mass shooting in Los Angeles County history said the gunman was previously arrested for illegally possessing a firearm, had a rifle at home, hundreds of rounds of ammunition and appeared to be manufacturing gun silencers.