Man who killed officer said he was hit by ultrasonic waves

DAVIS, Calif. (AP) — Among the evidence recovered from the home of a man who shot and killed a rookie California police officer were two unregistered guns and a letter claiming police had been bombarding him with ultrasonic waves.
Police in the city of Davis on Saturday released the letter they say was written by Kevin Limbaugh.
The 48-year-old killed himself Thursday after fatally shooting Officer Natalie Corona.
Limbaugh wrote police targeted him with ultrasonic waves for years, saying &