An employee of a southeast Iowa drug treatment facility has been found murdered and a resident of the center is charged in the killing. 44-year-old Kathi Mertens of Mount Pleasant had been working the overnight shift at Alcohol and Drug Dependency Services in Burlington. Her body was found about 8 Wednesday morning at the facility. 19-year-old Ryan Wichart of North Liberty, a resident of the center, is charged with first-degree murder. Wichart was picked up at a Burlington grocery store in Mertens’ car. He was also charged with public intoxication. It’s still unknown how Mertens died. An autopsy is scheduled. Wichart is held without bond in the Des Moines County Jail.