HUDSON, Wis. — A Wisconsin man who killed his three daughters to get back at his ex-wife will soon learn if he’ll spend the rest of his life in prison.

A jury found in April that 35-year-old Aaron Schaffhausen was sane when he killed 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia at their River Falls’ home. He’ll be sentenced Monday in St. Croix County.

He faces a mandatory sentence of life in prison for each death. The judge must decide if that sentence will include the possibility of supervised release after at least 20 years, or if Schaffhausen will stay behind bars forever.

Schaffhausen admitted he killed the girls last July to get back at his ex-wife. Jurors found he had a mental defect, but knew the killings were wrong.