Aaron Schaffhausen pleaded guilty Thursday to all four charges of killing his three young daughters in July, The Pioneer Press reported.
The second phase of the trial will determine if Schaffhausen's mental state at the time absolves him of the crimes, The Pioneer Press reported.
Jessica Schaffhausen, his ex-wife, agreed to let him see their children unexpectedly but asked him to leave the house before she returned home, The Star Tribune reported.
Schaffhausen will wither go to a psychiatric facility or prison potentially for the rest of his life depending on the decision of the second phase of the trial, The Pioneer Press reported.
Schaffhausen is remorseful and depressed, John Kucinsh, Schaffhausen's lead attorney told the Pioneer Press.
If Schaffhasuen is sentenced to a psychiatric facility, a judge could order his release it is determined he is no longer a threat to the public, Kucinski told the Pioneer Press.
If the jury rejects the insanity defense, he would receive three life sentences, The Pioneer Press reported.