A Mississippi Department of Corrections employee has been arrested on charges of embezzlement after officials say he stole prison property and sold it for personal profit.

Corrections Commander Carl Arnold, 60, was arrested Tuesday and suspended without pay, Commissioner Burl Cain said Friday afternoon. Arnold, a 25-year veteran of the department, is accused of taking state-owned copper and stainless steel and selling the items to a private business. Officials allege the illegal activity had been going on for almost a year.

Arnold was head of the K-9 unit at the Central Mississippi Correctional Facility in Pearl. It wasn’t immediately known if he had an attorney who could comment for him.

Cain, who was confirmed as Mississippi’s corrections commissioner in June, said Arnold’s arrest is part of a greater effort to quash wrongdoing by employees in the Department of Corrections. Arnold was one of five employees, including the chief of security and a warden, who have been dismissed or suspended since Cain started work.

“We are the ones who are supposed to be protecting society from the criminals, not be the criminals,” Cain said in a statement. “So we will not tolerate bad behavior of any kind.”

Citing confidential personnel issues, Cain said he could not publicly discuss why the chief of security and one of the wardens were terminated. He also couldn’t discuss the reasons for suspending a director and an associate warden without pay. A sixth employee resigned effective immediately and is prohibited from going on prison grounds. Four other people, who are not state employees, have also been banned from the Rankin County prison.

Cain said he will be as transparent as he can be and keep the public informed of any additional criminal charges tied to the employees.

For years, Mississippi prisons have operated with tight budgets and have struggled to hire enough guards because of low pay, long hours and dangerous conditions. Outbursts of violence in late December and early January left several inmates dead or injured. Lawsuits filed on behalf of prisoners say living conditions are unsanitary. And the U.S. Justice Department announced in February that it is investigating the Mississippi prison system.

A previous Mississippi corrections commissioner, Christopher Epps, is in federal prison after pleading guilty in 2015 to money laundering and filing false tax returns. Prosecutors said he took more than $1.4 million in bribes from contractors doing business with Mississippi prisons.

Cain spent 21 years as warden of Louisiana’s Angola penitentiary before his nomination to the the job of corrections commissioner in Mississippi.