SAN JOSE, Calif. (KRON) — Local authorities said Friday that they were not aware of Samuel Cassidy’s books on terrorism and his writings regarding hatred towards work.

San Jose officials said they weren’t notified in 2016 after federal officers detained Cassidy, the gunman in Wednesday’s mass shooting at VTA rail yard, and found him with books about terrorism.

Federal authorities also found Cassidy with writings detailing his hatred of the rail yard.

Officials said the information could have helped local law enforcement and the shooter’s employer potentially prevent the deadly attack that took the lives of nine employees.

“The DA’s office was not notified,” District Attorney Jeff Rosen said in an interview. “I would like to have known this in 2016.”

This story will be updated.