CASPER, Wyo. (AP) — Investigators say a Wyoming man facing a second-degree murder charge told them he broke into his parents’ home and shot his mother when she confronted him in the living room.

The Casper Star-Tribune reports 27-year-old Andrew Steplock showed up uninvited at his parents’ house in Casper on Monday and argued with his mother. Charging documents state Steplock’s mother, 58-year-old Deborah Steplock, removed a key to her house from his keychain while he was showering and replaced it with one that didn’t work. She then told her son he wasn’t welcome to come by uninvited.

Detectives say Andrew Steplock told them he decided to steal money from the home and broke in early Tuesday morning after his key didn’t work. He’s accused of shooting his mother when she asked him what he was doing.

It’s unclear if Steplock has an attorney.