DULUTH - A Duluth man who said he doesn't remember killing his girlfriend pleaded guilty to second-degree murder without intent Tuesday in St. Louis County Court — a plea deal that could land him in prison longer than sentencing guidelines would dictate.

Dale John Howard, 25, told Judge Theresa Neo that he doesn't remember it but believes he caused the death of his girlfriend, Allisa Marie Vollan, 27, on March 22. Vollan, described on a fundraising site as a "bright young lady" with "an abundance of friends," had a no-contact order against Howard at the time of her death. Howard could be sentenced to 20 years in prison — more than seven years longer than Minnesota's presumptive guideline for the murder. According to the County Attorney's Office, the longer sentence is legal because of the active domestic abuse no-contact order against him.

Howard's sentencing is scheduled for Oct. 14.

According to court documents, officers responded to a morning call at Howard's Central Hillside apartment and found him beneath a blanket with Vollan, who was dead. He told officers that he had hung out with Vollan late the previous night, then left to meet friends at a bar, and Vollan went to sleep in a guest room. When he tried to move her into his bedroom the next morning, she wasn't breathing. He called his father, who was at the apartment when Duluth police arrived.

Neighbors in the upper level of the duplex told officers that, in the time before Howard would have left for the bar, they heard a woman crying and an angry male voice. They heard muffled moaning, thuds and the sound of something being dragged. They recorded it.

A preliminary autopsy by the Midwest Medical Examiner's Office found that Vollan had likely been smothered.

Earlier the same month, Howard was arrested after neighbors saw him repeatedly slam Vollan's head into a door. The no-contact was issued by a St. Louis County judge.