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 at the troubled facility over the past year.

Waupun Correctional Institution’s warden, Randall Hepp, is charged with misconduct in public office, Dodge County Sheriff Dale Schmidt, who led the investigations, said at a news conference. The other eight face charges of inmate abuse, which is a felony. All nine had court appearances Wednesday, the sheriff said.

“We are operating the oldest prison in the state of Wisconsin in a dangerous and reckless manner,” Schmidt said, referring to the Waupon facility.

If convicted, Hepp faces up to 3 1/2 years in prison and a $10,000 fine.

Since last June, four inmates have died at the prison, which is the oldest still operating in Wisconsin. Three of the deaths are subject to federal lawsuits, the state Department of Corrections is investigating the prison’s operations, and the governor last year asked the U.S. Department of Justice to get involved.

Hepp announced last week that he planned to retire at the end of June and that Deputy Warden Brad Mlodzik would take over. He said in an email to Waupun staff that he had helped improve “safety and order” at the prison.

“It is amazing to know how far we have come,” Hepp wrote. “We also know we have more to do.”

The first of the four inmates who died, Dean Hoffman, killed himself in solitary confinement last June. Hoffman’s daughter filed a federal lawsuit in February alleging that prison officials failed to provide her father with adequate mental health care and medications.

Tyshun Lemons and Cameron Williams were both found dead at the facility in October. Dodge County Medical Examiner PJ Schoebel said Lemons overdosed on acetyl fentanyl, a potent opioid painkiller, and Williams died of a stroke.

Donald Maier was found dead at the prison in February. Authorities have not released any details in that death.

Waupun’s problems don’t end there. Gov. Tony Evers’ office said in March that federal investigators were looking into a suspected smuggling ring involving prison employees.

At the time, the governor’s spokesperson, Britt Cudaback, said sweeps of Waupun housing units revealed people in the prison were obtaining prohibited items such as cellphones and illegal drugs. An initial investigation by the Department of Corrections uncovered allegations that prison employees were involved, including information suggesting “financial crimes” may have occurred, she said.

At least 11 prison employees have been suspended in connection with that probe.

The state Department of Corrections imposed a lockdown at Waupun, and at prisons in Green Bay and Stanley last year due to a shortage of guards. Waupun inmates filed a federal lawsuit in October alleging the the conditions amounted to cruel and unusual punishment. That lawsuit is still pending.

Stanley resumed normal operations in November. Movement restrictions have eased at Waupun and Green Bay, but as of the department’s latest update in April, in-person visitation had not resumed at Waupun and recreation time was still limited. Prisoners were being allowed to make phone calls and text using electronic tablets, however.

Waupun is one of five maximum-security prisons in Wisconsin. The facility, built in the 1850s, held 712 inmates as of May 31, according to the state Department of Corrections latest population report. The prison is designed to hold up 882 inmates.

(AP)