The warden of a maximum-security Wisconsin prison and eight members of his staff were charged Wednesday following investigations into the deaths of four inmates over the past year, including one that wasn’t discovered until at least 12 hours after the man died.

Waupun Correctional Institution’s warden, Randall Hepp, is charged with misconduct in public office. The other eight face charges of inmate abuse, which is a felony, and three of them — two correctional officers and a correctional sergeant — are also charged with misconduct in public office. All nine had court appearances Wednesday.

“We are operating the oldest prison in the state of Wisconsin in a dangerous and reckless manner,” Dodge County Sheriff Dale Schmidt, who led the investigation, said at a news conference announcing the charges.

One inmate whose death was ruled a homicide had his water turned off for a significant amount of time, wasn’t closely monitored despite refusing to eat, and didn’t have direct contact with a doctor because he was in restrictive housing, Schmidt said. Another inmate who had a stroke was dead in his cell for at least 12 hours before he was found.