Police say a pastor and former South Carolina mayor is accused of having inappropriate conduct with a "vulnerable" hospital patient diagnosed with a cognitive condition that inhibits their decision-making.

Johnnie Waller, 71, was arrested after Greenwood police officers received a report on Sept. 27 from staff at the Self Regional Medical Center concerning "a situation in a patient’s room that prompted immediate concern," the department said in a Facebook post on Thursday, Oct. 9. Police described Waller as a community member who was known to visit patients under a pastoral role.

The Sept. 27 incident allegedly involved Waller having an inappropriate sexual encounter in the room of a long-term patient under the care of the Department of Social Services, police said.

Due to the nature of the encounter and the patient's diagnosed cognitive condition, an investigation was started to determine if a crime had occurred, according to the department. Police added that the patient, who has been under medical care at Self Regional since early 2025, had been deemed to "lack decision-making capacity by multiple physicians."

After investigators collected and reviewed surveillance footage from the hospital, gathered statements from staff and conducted interviews with relevant parties, a warrant for third-degree criminal sexual conduct was issued for Waller, police said. He was subsequently booked in the Greenwood County Detention Center and barred from all Self Regional Healthcare properties, the department added.