In 2016, US Customs agents detained Samuel James Cassidy, the man who reportedly shot and killed nine people at the Santa Clara Valley Transportation Authority on Wednesday, because he possessed books and information on terrorism and fear, the Wall Street Journal reports.
Cassidy also possessed a manifest in which he described his hatred of his workplace and coworkers, according to a memo released by the Department of Homeland Security. He possessed “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” when he returned to the United States from the Philippines.
Customs and Border Protection detained Cassidy and questioned him, but according to the memo, he declined to admit having any significant issues with his coworkers.
The WSJ could not determine if the memo was shared with any local law enforcement or with his employer.