June 2 (UPI) -- Authorities have yet to announce a motive in the mass shooting last week at a rail yard in San Jose, Calif., that killed nine people, but they have released police body camera footage taken during the attack.
At a news conference Tuesday night, Santa Clara County Sheriff's Office released footage that showed the final minutes before authorities found gunman Samuel James Cassidy, who'd shot himself.
The four-minute video begins as officers climb a staircase at the Santa Clara Valley Transportation Authority's three-story office building. As police enter the main office area, gunshots can be heard. Two officers are seen moving toward Cassidy's body and grabbing his gun.
Asked about a possible motive at the news conference, Santa Clara County Sheriff Laurie Smith said the investigation is ongoing. Cassidy had worked at the transit agency.
She praised five law enforcement officers who first responded and said their following active shooting protocol saved lives.
"It was put into action by the sheriff's office and San Jose police officers who hardly spoke a word to each other, they knew what their job was, they did their job and then confronted the suspect," Smith said, according to The Mercury News.
Smith said it's likely Cassidy knew police were closing in and that caused him to shoot himself twice, in the chin and the side of the head.
An autopsy found the manner of Cassidy's death was suicide. Multiple gunshots can occur in suicides in which the first shot to the head is not immediately fatal, the Santa Clara County Medical Examiner-Coroner's Office said in a statement.
The Wall Street Journal reported last week that U.S. Customs officers detained Cassidy, 57, after a 2016 trip to the Philippines and had found books on terrorism in his possession, and a notebook expressing hatred for the transit agency.
Federal officials did not contact the transit agency or law enforcement, the Journal reported.