SAN JOSE (KPIX 5) – Four weeks after a Valley Transportation Authority employee killed nine of his colleagues in the deadliest mass shooting in Bay Area history, the agency released more personnel files on the gunman.

The documents shed more light into Samuel Cassidy’s work behavior as well as some of what he may have been dealing with in his personal life.

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Included in the nearly 100 documents released by the agency is a 2008 “written counseling” letter in which Cassidy was reprimanded for missing 11 days of work in a one year period. The letter was one step from a written warning.

In 2005, Cassidy failed to report to his supervisors every two weeks while on temporary disability for knee surgery, and was warned he could be terminated if he failed to check-in.

In 2019, Cassidy refused to sign out his portable radio, which is required when using the equipment. After multiple requests, according to the document, Cassidy was charged with insubordination and was sent home without pay for two days.

The 57-year-old missed work here and there in the last couple of years, according to his personnel files, including last August when he explained his absence was for “father emergency.”

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Two weeks ago, the agency provided this news outlet with other documents included in Cassidy’s personnel files, which paint a picture of possible growing tension at work in the last year.

It included a statement from a co-worker who told a colleague that Cassidy “scares me. If someone was to go postal, it’d be him.”

Cassidy had also gotten into a verbal altercation early last year with a coworker, refused to attend a mandatory CPR class last October, had an unexcused absence and inappropriately used his VTA radio the following month.

Despite his behavior, Cassidy appeared to continue to go to work without any further intervention or disciplinary action.

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On Wednesday May 26, Cassidy left his San Jose home and walked into his workplace with an arsenal of weapons and opened fire on his colleagues before turning the gun on himself. He planned the shooting to coincide with a fire he had set at his home.