The Maricopa County Sheriff's Office has release this short video clip showing an inmate being transferred to the psychiatric unit. On the video, a man deputies identified as the 31-year-old Gerster walked onto a table and put his foot down on the inmate's neck, holding him down.Investigators from the sheriff's office also linked Gerster to another case in which he watched over an inmate who was restrained in a bed. Gerster struck the inmate several times with a closed fist.Gerster is charged in two assaults, and is also accused of accessing a sheriff's office computer to get an inmate's address and providing it to a friend, who then assaulted the inmate, according to deputies.Gerster was already under investigation before the most recent assault happened, but was never removed from duty, the sheriff's office said.Investigators said it was the assault involving both the officers that brought the sheriff's office investigations together. Superiors said they learned of the problem after other officers came forward to report the assault.