The ex-girlfriend filed the court document in response to a domestic violence restraining order that Cassidy, 57, had filed earlier that month. She denied Cassidy’s accusations against her and alleged he had major “mood swings” as a result of bipolar disorder, which worsened when he drank large amounts of alcohol.

“He also played several mind games which he seems to enjoy,” she said.

In court documents, the woman detailed several instances of sexual assault. “Several times during the relationship he became intoxicated, enraged and forced himself on me sexually,” she wrote.

During those episodes, she said, he would hold her arms to her side and force his weight on her. Cassidy was 6-foot-1, 200 pounds, while the woman said she was 5-foot-4 and 120 pounds.

Cassidy tried to force anal intercourse on her several times, she wrote. She would fight him off, and he would later apologize and promise to never do it again, she said. She detailed another such incident in September 2008, when she said he pushed her on a bed and forced her to have sex with him.

In February 2009, another woman began living in his home, the woman said. Cassidy would become enraged when she would ask to meet this other person or ask what the extent of their relationship was, the woman alleged.

She also said in the court declaration that Cassidy stole tools and equipment from his current and former employers.

Emails between Cassidy and the ex-girlfriend indicated they had a contentious relationship, with Cassidy voicing displeasure over the woman’s friends — who disliked him.

“I know your friends are very mad at me and think badly of me,” he wrote in a December 2008 email. In that same email, he wrote about feeling “depressed over everything.”

In the emails, the woman called him a “f— game player” and “trouble maker,” and said, “all my girlfriends think you treat me s—.”

In Cassidy’s initital request for a restraining order —which was granted — he asked a judge to protect himself, a female roommate and his parents from the woman. He wrote of previous police visits to his house over an argument between the pair. He also accused the woman of surveilling him, vandalizing property and threatening to contact his employer to get him fired.

Authorities investigating the shooting did not immediately provide information about the gun or guns used in the shooting, and there was no indication that Cassidy was not eligible to buy or possess a firearm.

California has several protective order laws that make people ineligible for gun ownership, requiring them to give up their weapons and preventing them from legally buying new ones. Perpetrators of domestic violence or workplace harassment, and patients who undergo involuntary mental health evaluations, are among those subject to restrictions.

A more recent law allows police, immediate family members, roommates, employers, co-workers and school officials to seek the removal of firearms from someone they believe poses a danger to themselves or others.

Because the law does not require threats targeting a specific individual, advocates regard the gun violence restraining order, as it is known, as a key tool to prevent potential mass shootings, as well as suicides and other types of firearm deaths. California was one of the first states in the country to adopt this type of gun seizure law, though many law enforcement agencies have been slow to use it.

Santa Clara County Superior Court court records, though, indicate that Cassidy was not subject to any protective order that would have prohibited him from owning guns.

Julia Weber, implementation director for the Giffords Law Center to Prevent Gun Violence, said that raises questions about whether there were warning signs people should have followed up on — or if they even knew the options available to them.

“How do we ensure that people who know about threats take them seriously and pursue the protective gun safety policies in California that are designed to reduce risk?” she said. “If we don’t have the information, it’s that much more difficult to prevent this type of violence.”