According to police, Macario Perearamirez, 60, assaulted Frank Ramos, 51, with a hammer at the Rescue Mission, located in the 200 block of East Sixth Street. It was not clear why the assault occurred.
Police say Ramos then struck Perearamirez once in self-defense. Perearamirez fell and hit his head on the pavement.
When police arrived at the scene, they found Perearamirez unconscious with a head wound. He was taken to St. John's Regional Medical Center where he was treated for his injury.
Anyone with information about this incident is asked to call Oxnard detectives at (805) 385-7796.