Late Monday morning, deputies interviewed Sappington at the jail, where he claimed he was having sex with Sarten for a place to live, court records show. He told them he wanted to end the sexual relationship and took the revolver from under Sarten’s mattress, walked up behind her in the living room and fired at her before leaving, the affidavit says.

Susan Kerr, Sappington’s sister who now lives in Georgia, said the pair had a difficult childhood, which only worsened after their mother’s death in 1984. He went in and out of juvenile custody as a teenager, she said.

Kerr said she believed Sappington’s and Sarten’s alleged sexual relationship was not consensual and that Sarten was close to her mother when they were children.

“When you’re treated right by somebody and you’re surrounded by people who don’t do that, you don’t forget that,” Kerr said. “She was very nice, and everyone in my family has come from this continuous cycle of a bad childhood.”

Hill said Wednesday she was “extremely pleased” with the investigation and welcomes the opportunity to present the evidence against Sappington in court. The Oklahoma State Medical Examiner’s Office has not yet determined a final cause of death, and the state has not ruled out the possibility of additional charges being filed in the case, she said.