California police searched Monday for what compelled a 72-year-old man of Asian descent to shoot dead 10 people as they celebrated Lunar New Year at a dance hall in the Los Angeles suburbs.
The suspect identified as Huu Can Tran had once been a regular at the Star Dance Studio in Monterey Park, giving informal lessons there, US media said -- and he reportedly believed that other instructors said "evil things about him," an unnamed friend told CNN.
The network said it was unclear how frequently Tran had visited the studio in recent years.
He is believed to have arrived there around 10.20 pm on Saturday and opened fire inside, killing 10 people -- five men and five women, all in their 50s and 60s -- and wounding 10 more.
Then he apparently drove to another dance hall in nearby Alhambra, where authorities believe he intended to carry out a second massacre -- but was stopped by a 26-year-old employee who wrestled the gun away from him.
Security footage obtained by ABC shows the pair wrestling in the lobby of the Lai Lai Ballroom & Studio in Alhambra.
"From his body language, his facial expression, his eyes, he was looking for people," the employee, Brandon Tsay, whose grandparents founded the family-run studio, told the New York Times.
Tsay seized the gun from the suspect, pointed it back at him and yelled "Go, get the hell out of here," he told the newspaper.
The suspect fled. He shot himself inside a white van in Torrance, several miles to the south, on Sunday afternoon as police moved to arrest him.
Police have said the motive behind the attack, which came as Asian communities around the world celebrated the Lunar New Year holiday, remained a mystery.
CNN reported that Tran had met his ex-wife some 20 years ago at the studio in Monterey Park, a majority Asian American city.
The network did not identify the ex-wife, but said the pair met when Tran -- who was giving informal lessons -- spotted her and offered lessons.
He was an immigrant from China, CNN reported. The marriage did not last long, with the pair divorcing by 2006.
The ex-wife said Tran was never violent to her, but would become frustrated when, for example, she missed a step in a dance.
- 'Hostile' -
CNN also interviewed an old friend of Tran's who said at one point he was attending the studio "every night".
Tran was "hostile to a lot of people there," the friend said.
It was not clear if Tran was still a regular attendee at the Monterey Park studio.
Tsay, who told the New York Times he is a coder who works several days a week at his family's dance studio in Alhambra, said he had never seen Tran before.
Authorities had initially feared the attack was a hate crime targeting Asian Americans.
"We don't know if this is specifically a hate crime defined by law," Los Angeles Country sheriff Robert Luna told reporters Sunday, "but who walks into a dance hall and guns down 20 people?"
Monterey Park, only a few miles from downtown Los Angeles, is home to around 60,000 people, most of them Asian or Asian American.
Decorations erected in the city for the Lunar New Year hung above police tape Sunday.
Tens of thousands of people had gathered earlier for the two-day Lunar New Year festival, one of the area's largest. Events planned for Sunday were canceled after the attack.