HUDSON, Wis. (AP) — The man accused of killing his three young daughters in River Falls is facing an additional charge.

Prosecutors have filed an attempted arson charge against Aaron Schaffhausen. The 35-year-old father is already facing three counts of first-degree intentional homicide. Eleven-year-old Amara, 9-year-old Sophie and 5-year-old Cecilia Schaffhausen were killed July 10 in the home they shared with their mother, Schaffhausen’s ex-wife.

An investigator smelled gas in the basement of the River Falls home and found a gas container had been tipped over.

The Minot, N.D., construction worker is being held in the St. Croix County Jail on $2 million cash bond. An arraignment hearing is scheduled for Aug. 28.