Investigators Search for Motive Behind Lunar New Year Mass Shooting

Investigators continued Monday to search for a motive behind a shooting at a Southern California dance studio that left 11 people dead and a devastated community in mourning.

The shooting happened following a night of Lunar New Year celebrations in the San Gabriel Valley community of Monterey Park. About 20 minutes after the gunfire at Star Ballroom Dance Studio, the gunman targeted a second dance hall in the nearby community of Alhambra, where he was disarmed, authorities said.

In a statement released Monday morning, the Los Angeles County Department of Health Services said a victim hospitalized at LA County USC Medical Center has died, bringing the death toll to 11 people. One of the victims, was apparently shot while inside a vehicle before the gunman entered the dance hall, Sheriff Robert Luna said.

The man identified by the Los Angeles County Sheriff's Department as the shooter, 72-year-old Huu Can Tran, was found dead from a self-inflicted gunshot wound Sunday in a van in a Torrance strip mall parking lot, the sheriff's department said.

A motive in the shooting remains unclear, Luna said Sunday.

"That is something that investigators, we're trying to learn," Luna said. "We want to know what the heck happened here."

Multiple law enforcement sources familiar with the investigation told NBC News that while the exact motive remains elusive, evidence gathered so far suggests a personal motive rather than terrorism or a hate crime. The officials stressed the investigation remains in its early stages and that they're attempting to piece together a detailed timeline of events and more background on the gunman.

A search warrant was served Sunday at a Hemet senior center where neighbors said the shooter lived.

Sheriff Luna said Monday that at the home, investigators recovered several items, including one .308 mm caliber rifle, as well as hundreds of rounds of 0.308 mm and 0.9 mm bullets. Additionally, he said, investigators discovered items that led them to believe he was manufacturing homemade firearm suppressors, which are illegal in California. They also confiscated numerous electronics, including cellphones and computers, Luna said.

In a statement Monday, the Hemet Police Department said Tran went to the police station Jan. 7 and 9 "alleging past fraud, theft, and poisoning allegations involving his family in the Los Angeles area 10 to 20 years ago." Tran was advised to return with documentation supporting his claims, but never did so, the department said.

More details about the allegations and any possible connection to the tragedy in Monterey Park were not immediately available. Hemet police had no records of any incidents involving Tran in the community or calls for service at his home, according to the Associated Press.

Luna said his agency was looking into whether the allegations Tran made to Hemet police contributed to the "madness that occurred that day."

Speaking with NBC News, Monterey Park Mayor Henry Lo said the motive might have involved a personal relationship somehow connected to the dance hall. Lo said there appeared to be a "history of domestic violence," but did not provide more details.

"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 and we’ll probably find out more in the hours ahead or even days ahead," Lo said.

In an interview with CNN, the gunman's ex-wife said the two met at Star ballroom about 20 years ago when he offered to provide informal dance lessons. The two later married.

She told CNN Tran was a regular at the dance hall, but it's not clear whether he made recent visits. She said he was known to have anger issues, but was never physically violent toward her.

Tran filed for divorce in 2005 in Los Angeles County, court records show. NBC News has reached out to the person believed to be his ex-wife for comment.

“We all want answers to questions that we may never have answers to,” Monterey Park Police Chief Scott Wiese said. “That’s kind of the enigma of this. I know that my individual officers would like to know why. I know the families want to know why. The why is a big part of this. The problem is, we may never know the why.”

The victims were in their 50s, 60s and 70s. Two of the deceased victims were identified Monday morning by the Los Angeles County Coroner' Office.

Monterey Park is a city of about 60,000 people on the eastern edge of Los Angeles. The shooting happened in the downtown area where tents and red lanterns decorated the streets for the Lunar New Year festivities. A large banner proclaimed "Happy Year of the Rabbit!"

The Star Ballroom Dance Studio's website said it was hosting an event Saturday night called "Star Night" from 8 p.m. to 11:30 p.m. It was not immediately clear whether the shooter knew anyone at the dance hall event.

Congresswoman Judy Chu said she still has questions about the attack, but hopes residents now feel safe.

"The community was in fear thinking that they should not go to any events because there was an active shooter," Chu said, speaking at Sunday's news conference. "What was the motive for this shooter? Did he have a mental illness? Was he a domestic violence abuser? How did he get these guns and was it through legal means or not?"

The shooter was carrying what Luna described as a semi-automatic pistol with an extended large-capacity magazine. He fired 42 rounds, the sheriff said.

A second handgun was discovered in the van where Tran died in Torrance, authorities said.

It was unclear where or how he obtained the weapon recovered in Alhambra. That firearm, Luna said, was a .9 mm semiautomatic MAC-10 pistol that had been modified.

The sheriff noted that Tran

California law bans military-style assault weapons and high-capacity magazines, requires background checks for handgun purchases and allows law enforcement to petition for a court order to prevent a person in crisis from accessing a firearm, according to Everytown.

A vigil for the victims is scheduled for 7 p.m. Monday in Monterey Park.

The shooting was the was the nation’s fifth mass killing this month. It also marked the deadliest attack since May 24, when 21 people were killed in an elementary school in Uvalde, Texas.