FRAZEE, Minn. - A young man who has struggled with mental illness is now charged in the brutal murders of a friend and his mother in northwestern Minnesota.

A criminal complaint filed in Otter Tail Country details how prosecutors say William Hillman beat his victims to death with a pipe wrench early the morning of April 17 at a home between Perham and Frazee. Deputies were dispatched to the residence at 43230 505th Street after a resident reported that a man named William had assaulted his mother and brother. A short time later dispatchers received a call from a man, later identified as William Hillman, saying he had done a "bad thing" and needed to be arrested.

Investigators say 42-year-old Denise McFazden and her 21-year-old son Dalton were beaten to death with a pipe wrench.

When squads arrived at the home they found 42-year-old Denise McFadzen laying outside the trailer home and her son, 21-year-old Dalton McFadzen, on the ground just outside a bedroom inside. Both were dead on scene from blunt force trauma to their skulls. Investigators recovered a pipe wrench covered in blood and other matter.

Hillman was taken into custody and reportedly told detectives "I killed two people." He said he went to sleep about 10 p.m. the previous night, woke up early Tuesday and then "everything went black" and he didn't remember what happened next.

The defendant told investigators that he had assaulted his mother in the past and was committed to the St. Peter Regional Treatment Center, where he was diagnosed with schizophrenia. Records show he was released in November of 2017. At that time, he told authorities he went to stay with his father in California but was forced to return after his dad was put in jail. He lived with a friend in Detroit Lakes for a month before moving in with the McFazden family.

When a detective asked whether family members had ever threatened him, Hillman said no... they were just "weird." The defendant reportedly then said he would tell Denise and Dalton McFazden "I'm sorry... I'm sorry I did it."

If found guilty, William Hillman faces a potential 40-year sentence for each murder.