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.

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"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.

Wisconsin-Prison-Death-Investigations

Dodge County Sheriff Dale Schmidt talks about investigations into four inmate deaths that occurred at Waupun Correctional Institution during a news conference Wednesday, June 5, 2024, in Juneau, Wis. (AP Photo/Morry Gash)

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.

Hepp, who faces up to 3 1/2 years in prison if he's convicted, 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."

Hepp’s attorney Robert Webb did not respond to an emailed request for comment Wednesday.

Three of the four 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.

Jared Hoy, who heads the Department of Corrections, said in a statement that more than 20 people remain under internal investigation, at least eight are on administrative leave and nine others were fired or have retired since the probe began a year ago.

Given the ongoing investigation, Hoy asked the sheriff to keep his probe open and share all of his findings to date "as soon as possible and without any further delay."

Schmidt said he could reopen the investigation into more criminal charges if the internal state probe reveals additional evidence.

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. Schmidt said his death was ruled a homicide due to malnutrition and dehydration.

All of the charges are related to the deaths of Williams and Maier.

Waupun’s problems extend beyond the inmate deaths. Gov. Tony Evers’ office said in March that federal investigators were looking into a suspected smuggling ring involving prison employees.

Evers said Wednesday in reaction to the charges being filed that everyone who failed to do their job will be held accountable.

"There must be accountability and justice," Evers said in a statement. "And I believe accountability and justice insist that both internal and law enforcement investigations must continue until they have been exhaustively and thoroughly completed."

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.

Schmidt said he did not believe the lockdown had anything to do with the inmates' deaths.

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.

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Republican state lawmakers used the filing of charges to renew their calls for Evers to close the prisons in Waupun and Green Bay, which was also built in the 1800s.

"The warden may have been arrested, but the buck doesn’t stop there," said state Sen. Van Wanggaard, who chairs the Senate committee that oversees the state prison system. "Tony Evers can’t keep his head in the sand anymore."