FERGUS FALLS, Minn. - William Hillman, the man charged with the murders of a mother and son at their rural Frazee home, was recently found incompetent to stand trial and will be committed to the state mental hospital in St. Peter, according to Otter Tail County District Court documents.

Hillman, 22, is to be held in St. Peter until his mental health can be stabilized and he is declared competent to take part in the legal proceedings against him, according to a civil commitment order dated July 5.

Hillman faces two counts of second-degree murder in the case. He remained in custody Wednesday, July 18, at the Otter Tail County Jail.

He's accused of using a pipe wrench to kill 42-year-old Denise Mcfadzen and her son, 21-year-old Dalton Mcfadzen, on April 17 at their home.

Hillman, who lived with the Mcfadzens, told investigators that when he woke up that morning, everything went black and he didn't remember what happened next. He said when he came out of the blackness, he realized he had done "a bad thing," court documents said.

Court documents show it was determined that Hillman doesn't have the mental capacity to take part in criminal proceedings or assist in his own defense.

In a June 21 letter, forensic psychiatrist Gregory Hanson said Hillman was not cooperative in giving a full description of his actions, claiming amnesia. Hanson said he believed symptoms of mental illness made Hillman not competent to stand trial.

A report on Hillman's competency to take part in legal proceedings is required not less than once every six months. A review hearing is set for Dec. 17.

Hillman told investigators he assaulted his mother in the past and was diagnosed with schizophrenia and committed to the St. Peter Regional Treatment Center for a year and a half.

Court records show Hillman was declared mentally ill in 2016 in Cass County, Minn., and hospitalized in St. Peter after attacking and threatening to kill his mother on April 10, 2016, in her Pine River home. He was released from treatment in November 2017, court records said.

Hillman told investigators he was prescribed medication for his mental illness, but stopped taking it five months before the Mcfadzens were killed.