Surveillance video shows moments before VTA gunman left before shooting massacre

Surveillance video obtained by KTVU shows the moment 57-year-old Sam Cassidy left his San Jose home before storming into a work meeting at the VTA light rail yard and killed nine co-workers before killing himself.

Authorities also say that Cassidy set fire to his home on Angmar Court, which was reported two minutes after the 6:34 a.m. mass shooting at his workplace on Younger Avenue, a stone's throw from the Sheriff's Office, where detectives are trying to piece together the details of why Cassidy would kill his colleagues.

The video, taken from a neighbor's home security system, shows Cassidy dressed in a blue jumpsuit and heading down his driveway to a white pickup truck. He is also seen putting a large, black duffel bag into the truck before driving away.

SEE ALSO: What we know about the VTA light rail gunman Sam Cassidy

On Thursday, Santa Clara County Sheriff Laurie Smith told reporters that Cassidy had two semiautomatic weapons and 11 magazines. 

When authorities confronted him after the 6:30 a.m. Wednesday shooting, he killed himself.

Smith said her detectives are searching Cassidy's emails and texts, to try and figure out a motive.

"Those kinds of things may lead to something," Smith said, adding that so far, Cassidy had left "no written documents found that I'm aware of." 

She said that one of her employees had a relative who died in the massacre. 

As Smith was speaking, Cassidy’s home was still surrounded by caution tape.

As sheriff's deputies, San Jose police, the ATF and FBI were responding to the shooting at the light rail yard, firefighters were also responding to a fire at Cassidy's home, which authorities said was filled with ammunition and gasoline.

SEE ALSO: San Jose VTA shooting kills 10, including employee who opened fire

Ex-girlfriend details alleged abuse & 'mood swings' by VTA shooter, per court docs

Neighbors say he was not friendly.

Realtor Doug Suh, who lives across the street, told KTVU that he and his wife were scared of Cassidy. 

"I met him a lot of times," Suh said. "He never said yes or no. He'd just ignore me every time I'd see him. He was unfriendly. He didn't talk to anybody." 

Cassidy has no major criminal record in Santa Clara County.

But in 2009, an ex-girlfriend accused him of being "mentally, physically, and sexually abusive" in a restraining order she had sought against him. 

That woman told KTVU that Cassidy had complained about his coworkers and bosses and called the job stressful.

But she never thought he would be capable of killing someone.

KTVU reporters Evan Sernoffsy and Amber Lee contributed to this report.