SAN JOSE, CALIFORNIA (REUTERS) - Police and federal investigators on Thursday (May 27) sought to determine why a Northern California transit employee opened fire on his co-workers a day earlier, killing nine people, in the latest mass shooting in the United States.
Local authorities have declined to speculate on a motive for the shooting rampage, saying their work at the scene could take several days, assisted by the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
The gunfire erupted at about 6.30am Pacific time on Wednesday as the work day was beginning at a light-rail maintenance yard in the heart of Silicon Valley.
The accused gunman shot himself as police closed in on him minutes after he started firing, according to Santa Clara County Sheriff Laurie Smith.
The attack was the latest of at least nine deadly US mass shootings in the past three months, including a string of attacks at Atlanta-area day spas in mid-March and a rampage days later that killed 10 at a Colorado supermarket.
California Governor Gavin Newsom said at a Wednesday news conference the massacre was a symptom of a larger American problem.
"It begs the damn question, What the hell is going on in the United States of America? What the hell is wrong with us and when are we going to come to grips with this?" Newsom said.
A White House spokeswoman told reporters the shooting was further evidence that the United States was in the grip of an "epidemic of gun violence."
A Santa Clara County Sheriff's Office spokesman told CBS News that the gunman had two semi-automatic weapons and 11 magazines, while Sheriff Lauri Smith told CBS San Francisco that the weapons were pistols.
More than 24 hours after the shooting, officials had not publicly disclosed the name of the gunman. The San Jose Mercury News and other news media identified him as Samuel Cassidy, 57, a maintenance worker at the yard.
Firefighters responded to a fire at a home where the suspect lived at about the same time that the shooting was first reported. A police bomb squad searched the rail yard in San Jose and adjacent buildings after an explosive device was found.
The gunman and the nine victims shot dead were all employees of the transit agency situated near the city's airport. The victims were found in two buildings on the site.
The County of Santa Clara medical examiner-coroner's office identified victims late on Wednesday. All of them appeared to be male, ranging in age between 29 and 63.
Eight of the victims died at the scene: Paul Delacruz Megia, Taptejdeep Singh, Adrian Balleza, Jose Dejesus Hernandez III, Timothy Michael Romo, Michael Joseph Rudometkin, Abdolvahab Alaghmandan and Lars Kepler Lane.
A ninth, Alex Ward Fritch, 49, died late on Wednesday after he was taken to the hospital in critical condition, the medical examiner's office said, according to NBC Bay Area.
The city will hold a vigil in their memory on Thursday evening, Mayor Sam Liccardo said.
The suspect had worked for the transit authority since at least 2012, when he was listed as an "electro-mechanic," and was promoted to "substation maintainer" in 2015, according to records posted by the nonprofit website Transportation California.
His ex-wife, Cecilia Nelms, told the Mercury News on Wednesday that he would rant about his co-workers and bosses and would sometimes lash out at her. He complained about what he saw as unfair work assignments at VTA, she told the paper.
"When he was in a good mood, he was a great guy. When he was mad, he was mad," said Nelms, who was married to Cassidy until 2005.
In a March 2009 court filing posted online by the San Francisco Chronicle, a woman who said she had dated Cassidy for about a year described an abusive, volatile relationship in which he forced himself upon her sexually and "played mind games."
Cassidy, the woman said in a sworn statement, "exhibited major mood swings as a result of bipolar disorder" that worsened when he consumed large amounts of alcohol.
Court records show the case was resolved in April 2009.