Accused Santa Cruz killer Steven Carrillo was an Air Force sergeant who complained about about the police's use of force on Facebook before he allegedly killed Sheriff's Sergeant Damon Gutzwiller.
According to ABC7's Dan Noyes, the alleged shooter said "Who needs antifa to start riots when you have the police to do it for you."
Carrillo also wrote posts about the early warning signs of fascism which was on display at the US Holocaust Museum.
The FBI has said that they are investigating Steven Carrillo's role in the ambush and killing of a Santa Cruz sheriff deputy, which left two other officers wounded.
Carrillo is also being investigated in connection to the death of a Federal Security officer who was killed in an anti-racism riot in Oakland, California. Carrillo is reported to have been staff sergeant assigned to Travis Air Force base.
The FBI said in a statement that "the investigation into the incident in Ben Lomond, Calif. is ongoing."
"We are working with the Santa Cruz County Sheriff’s Department to determine a possible motive and/or links to other crimes committed in the Bay Area, to include the shooting of the FPS officers in Oakland," they added.
The Department of Homeland Security has since described the Oakland incident as an act of "domestic terrorism."
Carrillo faces charges of first degree murder while investigators attempt to determine the motive and circumstances behind the attack.