The gunman who fatally shot nine people at a Northern California light rail hub earlier this week stashed an arsenal of weapons and ammunition at his home, which he set on fire as part of his planned rampage.
Samuel James Cassidy, 57, had several cans of gasoline, suspected Molotov Cocktails, twelve firearms, and about 22,000 rounds of various types of ammunition at his home, the Santa Clara County Sheriff's Office said in a statement Friday.
"It is clear that this was a planned event and the suspect was prepared to use his firearms to take as many lives as he possibly could had Sheriff’s Deputies not made entry to stop his rampage," the office said.
Before the gunman left his home Wednesday morning, he set a timer or slow-burn device to set his home on fire, according to Santa Clara County Sheriff Laurie Smith. At the scene, he had three semi-automatic 9mm handguns along with 32 high-capacity magazines loaded with additional ammunition, she said.
While officers initially found "potential explosive precursor materials" at the gunman's residence and the Santa Clara Valley Transportation Authority, they ultimately did not find any explosives, the office said.
"The suspect has been described by fellow co-workers as being disgruntled, and detectives are investigating his relationship with the VTA," the office said.
'Such extreme steps':San Jose killer intricately planned rail attack with a simple motive in mind
In 2016, U.S. Customs and Border Protection stopped Cassidy on a trip back from the Philippines and found that he expressed hatred of the rail yard where he worked, according to a Department of Homeland Security memo from the stop obtained by The Wall Street Journal.
An officer found Cassidy had "books about terrorism and fear and manifestos ... as well as a black memo book filled with lots of notes about how he hates the VTA," according to the memo. When he was asked if he had problems with anyone at work, Cassidy said, "no," according to the memo.
Local law enforcement in the San Jose area was never notified of the memo or Cassidy being detained, Santa Clara County District Attorney Jeff Rosen said in an interview with USA TODAY. He noted his office, along with local authorities and the gunman's employer, may have been able to interject and halt the attack from ever occurring.
"The DA's office was not notified," Rosen said, adding he wasn't aware of a single agency in the area that was told this information. "I would like to have known this in 2016."
A VTA spokesperson Friday, responding to a question about whether Cassidy ever said or did anything to make employees uneasy, said the authority was reviewing all records that pertain to Cassidy.
Here's what we know Friday:
Gunman's father says he was blindsided by attack
The gunman's father on Friday said he saw his son just two days before the attack and felt blindsided by what happened.
"He came over to help his mom with her car," James Cassidy, 89, told The Mercury News. "He seemed fine."
The father told the outlet there was "no hint" of what his son had planned, adding they didn't see Samuel Cassidy that often and rarely heard him complain about anything.
"He never really indicated anything was wrong at all," James Cassidy told The Mercury News.
But, his father did say that his son suffered from bipolar disorder, though it was "no excuse" for what happened. The gunman's father does not indicate whether he was diagnosed with the disorder or whether he'd ever been treated.
Witnesses say shooter targeted specific people, was an 'outsider'
The contents of the memo align with the picture law enforcement has painted so far of a man who appears to have kindled hatred against the people he worked with for a decade.
As Cassidy gunned down nine other employees before taking his own life, witnesses say he targeted specific people. Smith, the sheriff, said Cassidy told at least one person "I’m not going to shoot you," before shooting others.
"So I imagine there was some kind of thought on who he wanted to shoot," Smith said.
Kirk Bertolet, a signal maintenance worker who worked in a separate unit from Cassidy, told the Associated Press that the suspect didn't hurt people he encountered on the way to the second building, where more shots were fired.
"Sam made sure he killed all who he wanted. He made sure they were dead," Bertolet said. "I watched some of my coworkers breathe their last breaths, and they were all gone. Seven of them were just gone."
Bertolet called Cassidy an "outsider," saying, "He was never in the group. He was never accepted by anybody. You look back and you go, ‘yeah, it fits.'"
Who were the victims?
Nine people died in the shooting, and among the victims were bus and light rail operators, mechanics, linemen and an assistant superintendent.
The victims were: Paul Delacruz Megia, 42; Taptejdeep Singh, 36; Adrian Balleza, 29; Jose Dejesus Hernandez, 35; Timothy Michael Romo, 49; Michael Joseph Rudometkin, 40; Abdolvahab Alaghmandan, 63; Lars Kepler Lane, 63; and Alex Ward Fritch, 49, according to the Santa Clara County coroner's office.
VTA light rail maintenance operations manager George Sandoval said at a Thursday news conference that there is a strong connection among many of the agency's employees.
"Many of these folks worked here for 20, 30 years, so yes, we do become a family," Sandoval said. "Our staff respond to emergencies on the rail and there’s a bond."
He tried to warn his co-workers, then he was shot: Loved ones mourn victims of shooting at San Jose rail yard
Victims honored at vigil
About 1,000 people gathered Thursday night at a vigil outside of San Jose's city hall as family members tearfully remembered their loved one as heroes and role models.
Taptejdeep Singh's brother, Karman, said his brother had a "lion's heart." As the gunman opened fire, Taptejdeep Singh rushed out of the safety of an office to help others escape, witnesses told his family.
Annette Romo, whose husband Timothy Michael died, told the crowd, "Never leave home without giving your loved one a kiss. Cause that was the last I got."
A GoFundMe spokesperson said a centralized hub for identifying and verifying fundraisers for the victims and their families has been set up at gofundme.com/san-jose-strong.
Suspect prepared for the shooting for years, police say
Police say Cassidy plotted intricately for the shooting. He gathered weapons, read about terrorism, harbored bomb-making materials and rigged his home to go up in an inferno as he set out to kill nine fellow employees.
Before Cassidy left his home around 5:39 a.m., he set a timer or slow-burn device to set his home on fire, said Smith, the Santa Clara County sheriff.
Authorities say they found an assortment of what appeared to be bomb-making materials in Cassidy's locker — forcing a lockdown of the area and bomb technicians to sweep the large complex.
Those who knew Cassidy said he had anger and alcohol issues, threatened workplace violence and talked for years about his hatred of his workplace.
Cecilia Nelms, who was married to Cassidy for about 10 years before they filed for divorce in 2005, told The Mercury News that he was often was angry at coworkers and about his assignments at work, though she said she hasn't spoken with him in about more than a decade.
Another woman who dated Cassidy accused him of rape and sexual assault, according to court documents from 2009 obtained by The Mercury News. The documents also include accusations that Cassidy had severe mood swings and suffered from alcohol abuse.
Contributing: John Bacon, USA TODAY; The Associated Press
This article originally appeared on USA TODAY: San Jose shooting: Samuel Cassidy had weapons, ammunition at home