A 30-year-old Stillwater man, David Joseph Janisch, has pleaded guilty to stabbing his father to death in October.

Gregory Janisch, 57, died about 90 minutes after his son stabbed him in the chest, penetrating his heart.

"My son, he's bipolar," Gregory Janisch told police arriving at their house on the 2200 block of Countryside Court.

David Janisch pleaded guilty Friday to second-degree murder in Washington County District Court. Judge Gary Schurrer set sentencing for May 20.

The county attorney's office will argue for a prison sentence of 22 to 31 years, said Susan Harris, chief of the criminal division. That's consistent with state sentencing guidelines, she said.

According to a criminal complaint, David Janisch called 911 after he stabbed his father. An officer, finding David Janisch in the front yard, used a Taser to subdue him. Gregory Janisch was found lying in a pool of blood in the entry of the house.

Police also found a knife next to him. The Ramsey County medical examiner said he died of a single stab wound to the heart.

Janisch remains in the Washington County jail in lieu of $1 million bail.

KEVIN GILES