Could managers have predicted that Sam Cassidy, the Santa Clara Valley Transportation Authority employee who killed nine of his co-workers before turning the gun on himself, would have committed such a crime?

That's what VTA staff and local leaders are trying to answer now through an investigation of Cassidy's personnel history as a VTA employee following the May 26 mass shooting.

“So far, there is no indication of records in Cassidy's VTA personnel file of any formal discipline for threatening behavior or violence during his 20-year career at VTA," the VTA said in a statement this week..

As authorities examine what drove the East San Jose loner to burn down his house, then unload automatic weapons at specific employees at his workplace in San Jose, a picture of an angry, disgruntled transit worker is emerging.

Cassidy's record may not have indicated violent behavior, but his record wasn't clean, according to limited data released by the VTA on June 10.

Records show the killer had been sent home for insubordination because he refused to comply with company policy to sign out a two-way radio that was necessary to perform his job in July 2019.

He also refused to attend CPR certification in October 2020 citing COVID-19 concerns.

Most recently, personnel records released by the VTA revealed that in November 2020, Cassidy left work without permission because of frustrations with clocking in. He also used the radio communications for personal communication instead of operational matters, which is against VTA policy.

“He left work without permission instead of resolving the problem,” the VTA said.

Ten months earlier, on Jan. 29, 2020, a verbal altercation between Cassidy and another VTA employee was reported to VTA Employee Relations and the VTA Office of Civil Rights.

In an email to VTA leadership, an employee wrote that Cassidy yelled at a female co-worker for about two to three minutes, calling that person the “most corrupt person at VTA.”

Many Amalgamated Transit Union representatives and co-workers were there when the altercation broke out and an ATU representative had told Cassidy that “this was not the time or the place.”

The altercation subsided at that point, however, upon questioning from a supervisor, a co-worker reported that another unnamed employee said, “He (Cassidy) scares me. If someone was to go postal, it'd be him.”

Because there were no other disciplinary incidents of concern, there was no further investigation and disciplinary action was referred to Cassidy's management, according to the VTA.

The VTA said it is still reviewing “housands of pages of documents that include emails, attachments, and other materials" that require review and will be released "as soon as practical,” and with respect to co-workers' privacy.

The VTA also said among the thousands of documents, they had not found information about Cassidy being provided by any federal agency, including the Department of Homeland Security, The Wall Street Journal reported that Cassidy had been detained by U.S. Customs and Border Protection after he took a trip to the Philippines. There, authorities found books on terrorism and a notebook with complaints about the VTA in Cassidy's possession.

Santa Clara County District Attorney Jeff Rosen said federal agents did not inform local law enforcement.

At a news conference this week at San Jose City Hall, Rosen said he is working with San Jose Mayor Sam Liccardo to create information-sharing protocols with different law enforcement agencies to avoid something like that happening again.

The VTA said it will continue to release documents pertaining to Cassidy “if more relevant information is discovered.”

Jana Kadah is a reporter with Bay City News.