Authorities are investigating a Vallejo police officer who pinned a man to the ground, punching and hitting him with a flashlight, in a confrontation caught on video.
KNTV reports that the incident happened Friday at a gas station after police were called about a man acting erratically, threatening people and simulating a gun with his fingers.
Footage of the confrontation shows the officer hitting the man three more times after a second officer arrived to help subdue the man.
One officer was injured during the confrontation. The man was arrested for resisting arrest and being under the influence. His condition was not available Monday.
Police said the officer will remain on leave during the investigation and said officers should be considered innocent until proven guilty.