FERGUS FALLS, Minn. — A judge will decide whether a Pine River, Minn., man’s mental illness can be used as a defense argument in connection to the bludgeoning death of a woman and her son more than two years ago in Otter Tail County.

William Lynn Hillman, 24, waived his right on Thursday, Nov. 12, for a jury to decide if his mental illness prevented him from understanding that killing 42-year-old Denise McFadzen and her son, 21-year-old Dalton, at their mobile home in Frazee, Minn., was wrong. He also declined to have witnesses testify in court.

Otter Tail County Judge Kevin Miller will rule on the case based on evidence and reports completed by mental health experts who evaluated Hillman.

Attorneys now have until Nov. 23 to submit additional reports. Miller said he expects to file findings of fact for the case by Nov. 30.

Denise Mcfadzen and Dalton Mcfadzen
Denise Mcfadzen and Dalton Mcfadzen

WDAY logo
listen live
watch live
Newsletter signup for email alerts

It’s been almost three years since Hillman was arrested in connection to the April 17, 2018, killings. Prosecutors argued Hillman was living with the McFadzens when he beat them to death with a pipe wrench.

He claimed he “blacked out” but knew he did a “bad thing” when he came to his senses, investigators said in a criminal complaint.

Hillman's mental illness has contributed to his criminal activity, according to past court filings. In this case, doctors have submitted differing findings on whether he met the standard to use mental illness as a defense.

In June, Miller found Hillman guilty of two second-degree felonies of murder after reviewing the case based on evidence alone — no testimony was given during that phase of the trial after Hillman waived his rights to have a jury and confront witnesses.

If Miller determines mental health played a role in the McFadzens’ deaths, Hillman will be committed to a treatment facility. If not, Hillman will be sentenced.

Each count carries a maximum punishment of 40 years in prison.