Investigators are also examining whether Mr. Tran visited a second location, the Lai Lai Ballroom & Studio, in search of people he wasn’t able to find at the Star, the official said. The two studios draw from the same cohort of dance enthusiasts, most of them middle-class immigrants from Asia, and investigators believe some people visited both dance halls on Saturday night. The attacks immediately halted Lunar New Year celebrations this weekend in Monterey Park, an Asian American enclave east of Los Angeles.
Mr. Tran had recently visited the police station in the city of Hemet — where Mr. Tran was living in a mobile home park, roughly 80 miles east of Monterey Park — to say that his family was poisoning him and orchestrating a scam to steal money from him, said Alan Reyes, the spokesman for the Hemet Police Department. He said Mr. Tran had visited twice to make the allegations — on Jan. 7 and Jan. 9 — and was told to come back with evidence. He never returned.
Police searched Mr. Tran’s home on Sunday and seized a rifle, several electronic devices, a large amount of ammunition and items that led detectives to believe he was manufacturing firearm silencers, Sheriff Robert Luna of Los Angeles County said on Monday. The sheriff also said that Mr. Tran was arrested in 1990 for unlawful possession of a firearm.
Sheriff Luna said investigators were still trying to determine the motive, and that they were looking into the possibility Mr. Tran was motivated by personal animosities or jealousy. He said it remained unclear if Mr. Tran had connections to the victims. “We’re hearing there were possible relationships there, but I’m not going to confirm that yet,” he said.
Mr. Tran, who was born in Vietnam, according to an immigration document, appears to have emigrated to the United States in the late 1980s. He was naturalized in 1990 or 1991, according to the document. Mr. Tran was married in June 2001 and divorced in May 2006, according to court records.
Mr. Tran several years ago had been a frequent presence at the dance studio where the killings occurred and often clashed with people there, nursing grievances that lasted for years, according to a man who once befriended him and joined him some nights at the Star Ballroom.
“I was surprised,” the man, Adam Hood, said, describing his reaction when he heard of the massacre. “But in the same token, I was not surprised. I was surprised, you know, this is such a horrible massacre, that someone would have done this. When I say I’m not surprised, because if I know him well enough, this would have happened sooner or later.”