The gunman behind the deadly dance hall shooting in the Los Angeles suburb of Monterey Park may have been targeting his ex-wife on the Lunar New Year, the city's mayor said Monday.
That revelation came as investigators are focused on a personal motive and have discounted hate crime or terrorism as a possible inspiration for the attack, multiple law enforcement officials familiar with the investigation said.
The officials emphasized that it's early in the investigation but said evidence gathered at the suspect's home and in the van where he was found dead of a self-inflicted gunshot wound Sunday afternoon so far suggests the bloodshed was somehow personal.
The death toll from Saturday's shooting climbed to 11 Monday, with at least nine other people being treated for their wounds, officials said. Los Angeles County Sheriff Robert Luna said Monday afternoon the suspect fired 42 rounds at the Monterey Park venue.
The sheriff said the gunman used a MAC-10, a compact semiautomatic and sometimes automatic firearm. The weapon was wrested at a second dance hall by a man being hailed as a hero.
Luna has called the firearm an "assault weapon."
On Sunday, the sheriff said he believed such a gun may be illegal to possess in California, but the legality of the weapon was unclear Monday.
Luna said the Bureau of Alcohol, Tobacco, Firearms and Explosives and the FBI were helping to investigate.
Huu Can Tran, the 72-year-old suspected shooter, apparently thought his former wife was at the Star Ballroom Dance Studio when he burst inside and opened fire on a festive crowd, police said.
“My understanding is that he may have come because his ex-wife was reveling, celebrating the Lunar New Year, and it sounded like there was a history of domestic violence, which is unfortunate,” Monterey Park Mayor Henry Lo told NBC News’ Kate Snow.
Tran filed for divorce in 2005 in Los Angeles County, records show. NBC News has reached out to the person believed to be his ex-wife for comment.
What police found at suspect's home
Police on Monday continued searching the suspect's home in Hemet, a small city about 85 miles east of Los Angeles, and did not divulge a motive.
Luna said at an afternoon news conference that hundreds of rounds of loose .9 mm and .308 cal. ammunition was found at the residence, along with a .308 caliber rifle and evidence the suspect may have been making homemade firearms suppressors, which are illegal in California.
Alan Reyes, the public information officer for the Hemet Police Department, said their records show that Tran contacted them a decade ago and alleged his family was trying to poison him. The allegation was never investigated because Tran never presented any proof to back up his claims, he said.
Law enforcement officials said Tran lived at The Lakes at Hemet West, a gated “active living community” for people 55 and older more than an hour and a half south of Los Angeles.
The community sits on 150 acres in the San Jacinto Valley and includes a golf course, dog park, swimming pool, tennis court and other amenities.
Law enforcement officials executed a search warrant at Tran’s mobile home Sunday night, and multiple Los Angeles County Sheriff’s Office vehicles were seen exiting the property Monday afternoon.
Multiple attempts to enter The Lakes were denied by a security guard. A spokesperson for The Lakes declined to comment.
Tran died some 12 hours after the massacre of a self-inflicted gunshot wound inside a white van as a SWAT team closed in on him, Luna said Sunday.
A Norinco 9 mm handgun was found inside that vehicle, Luna said Monday.
Community mourns the victims
As the mostly Asian community braced for a wave of funerals, the Los Angeles Coroner’s Office released the names of some of the victims: My Nhan, 65, Lilan Li, 63, and Valentino Alvero, 68. It was not immediately clear if they knew the gunman.
A vigil is planned for Tuesday in Monterey Park.
“We believe that it is important for our community to come together to remember and heal,” Lo said in a statement.
At 72, Tran did not fit the age profile of a mass shooter. The median age over the past six decades is 32, according to data compiled by The Violence Project, a nonprofit research center funded by the National Institute of Justice.
Sheriff Luna said Monday afternoon that one of the dead was found in a vehicle just outside the Monterey Park venue, likely the first victim of the rampage. The others were killed inside, he said.
Threat at second dance hall
Some 30 minutes after Tran opened fire in the Star Ballroom Dance Studio, he turned up at another dance studio in the nearby town of Alhambra, police said. There, Tran was stripped of what police described as a “semi-automatic assault pistol” by a member of the family that operates the venue before he could harm anybody.
"When he came in, he said nothing,” Brandon Tsay, 26, told NBC News' Lester Holt on Monday. "His face was very stoic. His expressions were mostly in his eyes ... looking around trying to find people, trying to scout the area for other people."
Tsay said at first he "froze up" and was convinced he was going to die.
"But something amazing happened, a miracle actually," Tsay said. "He started to try to prep his weapon so he could shoot everybody, but then it dawned on me that this was the moment to disarm him, I could do something here that could protect everybody and potentially save myself."
So Tsay pounced and was able to wrestle the pistol out of Tran’s hands.
"That young man is a hero," Rep. Judy Chu, a Democrat who represents the district, said earlier Monday. "He saved so many lives."
Luna later agreed, saying, "What a brave man he is."
Tran was able to get away, police said. And about a dozen hours after the bloodshed in Monterey Park, police tracked his white van to a car park 30 miles away in the suburb of Torrance where the suspect killed himself.
Several pieces of evidence linking Tran to the carnage were found inside the van, Luna said. A handgun was also found in the van, he added.
A resource center was established at Monterey Park’s Langley Senior Center, he said, adding that mental health resources were available for "anyone who needs support."
Families and friends gathered at the center through much of Sunday, waiting to hear news of loved ones who they feared might have been among the people killed or injured.
“I tried to reach her, but I didn’t get any response,” Monterey Park resident Vivian King said of a friend she last heard from earlier in the weekend.
“It’s difficult not knowing what’s going on,” said Juan Pablo Pinzon, a tourist from Colombia, who said his cousin had been out with friends in the area Saturday night and had not responded to texts and calls. “Hopefully, we’ll hear something soon.”