CASPER (WNE) — A Natrona County jury took 101 minutes on Friday to convict a man of first-degree murder for the February killing of his mother in her central Casper home.

Andrew Steplock, 28, was also found guilty of second-degree murder, aggravated burglary and possession of a deadly weapon with unlawful intent.

The jury found Steplock both burglarized and attempted to burglarize his mother’s home on Feb. 26, when he shot and killed her. He then drove to Colorado, where he reportedly planned to live on the street. But police arrested him while he slept in his SUV near a gas station.

Steplock confessed shortly after his arrest but eventually took the case to trial, where his court-appointed defense team argued he should be found not guilty by reason of mental illness. Steplock said a voice in his head told him to kill his mother, the Casper Star-Tribune reported.