A Stillwater man has admitted strangling his girlfriend at her St. Paul home last summer and then inserting a cocaine-laced straw in her nose to make it look like an overdose.

Ivan Dan Walker, 34, pleaded guilty Friday in Ramsey County District Court to the second-degree unintentional murder of Shana Branch, 39, and the first-degree criminal sexual assault of a teenage house guest who was sleeping on Branch’s couch the night of the killing in July 2018.

Branch’s sons, ages 20 and 7, were in the home on Jessamine Lane at the time of the attack, and one of them called 911.

Ramsey County prosecutors said Walker will be sentenced in April to 30 years in prison as part of the plea agreement.

Walker is wanted on a warrant out of Missouri for a parole violation associated with a robbery conviction, according to court documents.