DAVIS (CBS13) — Investigators are releasing new information about the man they say shot and killed Davis Police Officer Natalie Corona.

Police say 48-year-old Kevin Douglas Limbaugh ambushed Officer Corona as she responded to a three-car accident near his home on 5th Street.

Limbaugh, they say, shot Corona several times and fired shots at other first-responders in the area, striking a firefighter in the boot.

ALSO: Suspect In Davis Officer’s Killing Identified As Kevin Douglas Limbaugh, 48

New tonight, police say Limbaugh wrote a letter, shedding light on his deadly plan.

Police say they have no reason to believe Limbaugh knew Officer Corona.

Yolo County court records show Limbaugh was arrested after assaulting a co-worker at the Cache Creek Casino Resort. He was charged with battery causing serious injury.

That was reduced to a misdemeanor after a plea, but Limbaugh spent eight days in jail and three years on probation.

No word yet on how he obtained the weapon he used to allegedly shoot Officer Corona.