Note left by gunman who killed California officer says he was hit by ‘sonic waves’

A letter mentioning “ultra sonic waves” was found after a gunman fatally shot a California police officer without warning this week before firing at others and later killing himself.
The letter was found face-up on his bed, said Lt. Paul Doroshov of the Davis Police Department. The Yolo County Sheriff’s Office deputy coroner identified the suspect Saturday as Kevin Douglas Limbaugh, 48, of Davis, California.
Limbaugh is believed to have opened fire on Davis police Officer Nata