Aaron Schaffhausen pleaded guilty to three counts of first-degree intentional homicide and one count of attempted arson in the July 10, 2012, deaths of daughters Amara, 11, Sophie, 8, and Cecelia, 5.
His lawyer maintained he was not legally sane when he killed the girls, but a jury concluded that while Schaffhausen had a mental disease or defect at the time, he was legally sane.
In a victim impact statements entered in St. Croix County Circuit Court in Hudson, the girls' aunt said Schaffhausen was the bogey man to his three daughters, the St. Paul (Minn.) Pioneer Press reported.
The girls' cousin and grandfather also spoke at Monday's hearing but Jessica Schaffhausen, the girls' mother, found it too difficult to speak, prosecutor Gary Freyberg said.
Judge Howard Cameron had discretion on whether to order Schaffhausen's sentences would be consecutive or concurrent, and whether the defendant would be eligible for release to extended supervision, the Minneapolis Star Tribune reported. Cameron determined Schaffhausen would not be eligible for extended supervision.
Cameron also can determine whether to set a later possible release date or if Schaffhausen will have no chance of release.
Prosecutors argued for the longest prison term possible, citing the severity of the crime, safety concerns for Schaffhausen's former wife, and the defendant's lack of remorse.
Defense attorneys emphasized Schaffhausen's mental health, arguing he had a debilitating mental illness not recognized by the average citizen. They cited Schaffhausen's history "replete with acts of love for those girls."