The suspect was reportedly employed by the Santa Clara Valley Transportation Authority, a bus and light-rail transit service that operates in Santa Clara County.
The victims, VTA employees, were working at a light rail maintenance facility.
© Peter Dasilva/Reuters ATF and Federal Bureau of Investigation agents approach the scene of the Santa Clara Valley Transportation Authority mass shooting suspect's house, after a fire at the home of the suspect erupted at about the same time as the shooting, in San Jose, Calif., May 26, 2021. The attacker took his own life, according to authorities.
Members of a union representing Valley Transportation Authority workers were meeting when the shooting began, San Jose Mayor Sam Liccardo said, but it's not clear the meeting was related to the attack.
It has not yet been determined whether those shot and killed were targeted.
In 2009, Cassidy had sought a restraining order against the woman, claiming she had threatened to get him fired from his job and had damaged a vehicle in his driveway. He was someone who could physically hurt others, she said. That's when he filed the restraining order against her, the report said.
She said he enjoyed playing mind games with her, according to the court document.
"Several times during the relationship he became intoxicated, enraged and forced himself on me sexually", the woman claimed.
His ex-wife, Cecilia Nelms, told The Associated Press that Cassidy had a bad temper and would tell her that he wanted to kill people at work, "but I never believed him, and it never happened". She denied the allegations, according to KNTV.
"He had two sides", Nelms said. "When he was in a good mood he was a great guy".
He often spoke angrily about his co-workers and bosses, and at times directed his anger at her, Nelms told the outlet. As he talked about it, "he would get more mad", she said. Security camera footage showed him around 5:45 a.m. - less than an hour before the massacre - leaving home wearing a blue jumpsuit and tossing a black duffel bag into a white pickup truck, according to the station.
The mayor said shootings of this scale are "uniquely American".
The neighbor later noticed a fire broke out at Cassidy's home around 6:30 a.m. The time was just minutes after police were called about the shooting at the VTA facility, about 8 miles away.
Neighbors knew Cassidy as a "very odd, very quiet" guy in his working-class neighborhood, said Ramon Crescini, 64, a retired general contractor who lives several doors down.
Liccardo said in an interview with CNN affiliate KGO that a fire was reported at the home of the gunman. Similar explosive materials were also found at his home, Smith said Thursday.