MONTEREY PARK, Calif. -- Investigators searching for a motive Monday in the worst mass shooting in Los Angeles County history said the gunman was previously arrested for illegally owning a firearm, had a rifle at home, hundreds of rounds of ammunition and appeared to be manufacturing gun silencers.
Los Angeles Sheriff Robert Luna said investigators had not yet established why 72-year-old Huu Can Tran gunned down revelers during a Lunar New Year celebration at a Monterey Park dance hall he was said to frequent.
"What drove a mad man to do this? We don't know, but we intend to find out," Luna said.
Tran fired 42 rounds at the Star Ballroom Dance Studio on Saturday night, killing 11 people and wounding nine. He then drove to another nearby dance hall where Brandon Tsay, who works at the establishment started by his grandparents, wrestled a modified 9 mm submachine gun-style semi-automatic weapon away from him and saved "countless lives," Luna said.
"He's the hero that disarmed the suspect," Luna said. "What a brave man he is."
Officers who had surrounded a van matching descriptions of the getaway vehicle found Tran dead inside Sunday from a self-inflicted gunshot wound. A handgun was recovered from the van.
Sheriff's deputies from Los Angeles County searched Tran's home in a gated senior community in the town of Hemet, a little over an hour's drive from the site of the massacre, Hemet police spokesperson Alan Reyes told The Associated Press.
Luna said his officers found a .308-caliber rifle, an unknown amount of bullets and evidence he was making homemade firearm suppressors that muffle the sound of the weapons.
Tran had visited Hemet police twice this month to report he was the victim of fraud, theft and poisoning by family members a decade or two ago in the LA area, Reyes said. Tran said he would return to the station with documentation but never did.
The mayor of Monterey Park said Tran may have frequented the first dance hall that he targeted, and his ex-wife told CNN she had met him there and he offered her free lessons.
The death toll rose to 11 Monday after health officials announced that one of the 10 people wounded had died, the LA County Department of Health Services said.
Los Angeles County Supervisor Janice Hahn said it was the worst mass shooting in the county's history.
All except one of the dead were 60 or older, according to information released Monday by the Los Angeles coroner's office providing the first identifications.
My Nhan, 65, Lilian Li, 63, and Xiujuan Yu, 57, were the three women named. Two other women were in their 60s, and one was in her 70s. Valentino Alvero, 68, was the only man identified. Three men in their 70s and one in his 60s were also killed.
Nhan's family said in a statement that she was a loving person whose kindness was contagious, and was a regular at the Star Ballroom Dance Studio.
"It's what she loved to do. But unfairly, Saturday was her last dance," the family said. "We are starting the Lunar New Year broken. We never imagined her life would end so suddenly."
Authorities have shared little about Tran, who once owned a trucking company, according to California business records.
Tran's Trucking Inc. was based in Monterey Park and licensed with the state from September 2002 through August 2004.
He had a previous arrest for unlawful possession of a firearm in 1990 and otherwise had a limited criminal history, Luna said. The sheriff could not immediately say if gun arrest at a time when firearms laws were different would have barred him from owning weapons.
Los Angeles Superior Court records show Tran was married in 2001 and divorced five years later, citing irreconcilable difference. The couple did not have children, said they had no community property and neither side had to pay alimony.
In the uncontested case, Tran noted in a filing that he could not get away from work to attend any court hearings, though he did not disclose where he worked or what he did.
His ex-wife told CNN that they married soon after they met at the dance hall. While she is named in court papers, she asked not to be identified because of the sensitivity of the case.
She said he would become upset if she missed a step dancing, but was never violent toward her.
Tran eventually moved from the San Gabriel Valley, a melting pot for Asian immigrants, and settled in Hemet, a lower-income community of many retirees 75 miles (120 kilometers) east of Los Angeles in Riverside County.
Tran lived in The Lakes at Hemet West, a gated community off a busy road with a view of snow-covered mountains. The development boasts of amenities including a 9-hole golf course, a shuffleboard court and a dance floor. Properties listed for sale ranged from $45,000 to $222,000.
A neighbor, Pat Roth, told KNBC-TV that Tran said he was a ballroom dance instructor in the past and would sometimes show up to dances at the senior community.
"Didn't seem like he'd harm a fly, you know. He wasn't a big guy," Roth said. "He'd pet your dog when you walked by."
Hemet police had no records of any incidents involving Tran in the community or calls for service at his home, Reyes said.
The shootings during Lunar New Year celebrations sent a wave of fear through Asian American communities and cast a shadow over festivities nationwide.
The massacre was the nation's fifth mass killing this month, and it struck one of California's largest celebrations of a holiday observed in many Asian cultures, dealing another blow to a community that has been the target of high-profile violence in recent years.
It was also the deadliest attack since May 24, when 21 people were killed in an elementary school in Uvalde, Texas.
"We do understand that he may have had a history of visiting this dance hall and perhaps the motivation has to do with some personal relationships. But that's something that I think investigators are still uncovering and investigating," said Monterey Park Mayor Henry Lo. Public records show Tran once had addresses in the city and neighboring ones.
Tran is the second-oldest mass killer in the U.S. over the last nearly 20 years according to a database compiled by The Associated Press, USA Today and Northeastern University. The only older mass killer was a 73-year-old who murdered five people in Yuma County, Arizona, in 2011 before killing himself. The database tracks every mass killing -- defined as four dead not including the offender -- committed in the U.S. since 2006.
Within three minutes of receiving the call, officers arrived at the Star Ballroom Dance Studio in Monterey Park, according to Monterey Park Police Chief Scott Wiese. Three of the officers were among the youngest on the force with less than a year of experience and they quickly encountered a scene of chaos with people running for their live and some of the wounded in the parking lot.
"Inside, they came across a scene that none of them had been prepared for," said Wiese, who was sworn in Thusday. "There were injured people inside, there were dead people inside and my young officers did their job, searched for a suspect and then came back and had to deal with the carnage inside. And it was extensive."
About 20 minutes after the first attack, the gunman entered the Lai Lai Ballroom in the nearby city of Alhambra.
Tsay, who was in the lobby, told ABC's "Good Morning America" that he thought he was going to die.
"Something came over me. I realized I needed to get the weapon away from him, I needed to take this weapon, disarm him or else everybody would have died," Tsay said. "When I got the courage, I lunged at him with both my hands, grabbed the weapon and we had a struggle."
Once Tsay seized the gun, he pointed it at the man and shouted: "Get the hell out of here, I'll shoot, get away, go!"
The assailant paused, but then headed back to his van, and Tsay called the police, the gun still in his hand.
Taxin reported from Hemet, Dazio reported from Alhambra and Melley reported from Los Angeles. Associated Press journalists Christopher Weber, John Antczak and Robert Jablon in Los Angeles, and Julie Watson in San Diego contributed to this report.