COVINA, Calif. (AP) — The man who killed nine people at his former in-law’s Christmas party while dressed as Santa Claus had plotted the attack several months ago and his hit list was longer than first thought.

Police said Monday that Bruce Pardo planned to also kill his mother and his ex-wife’s divorce attorney but committed suicide before he could complete the task.

Authorities said his plan was thorough and detailed. Pardo had a getaway car, an airplane ticket to the Midwest, several guns, and high-powered ammunition only sold outside the state.

Police Lt. Pat Buchanan said Pardo knew his mother had been invited to the party and intended to kill her because he felt she sided with his ex-wife in their divorce. Lucky for her, Buchanan said, she felt ill and opted to stay home.