Police have arrested a River Falls man in connection with the deaths of his three daughters. The city’s police chief says it’s the worst crime he’s ever seen in his community.

Aaron Schaffhausen turned himself in Tuesday afternoon and is now facing three counts of first degree intentional homicide in the deaths of 11 year old Amara, 8 year old Sophie and 5-year-old Cecilia Lee. During a press conference, River Falls Police Chief Roger Laque said the girls’ mother, Jessica Shaffhausen, alerted authorities Tuesday afternoon that her husband said he was coming and that he threatened to hurt their children. Police Chief Roger Leque says officers were dispatched to search her home. “In the process of the search the gas fireplace was found to be activated and an odor of what was believed to be a flammable liquid in the basement level,” he said.

Police found the bodies of the three daughters but have not yet released the cause of death. Autopsies on the victims are being performed at the Ramsey County Medical Center in Minneapolis. Laque says the event has shaken the small city in western Wisconsin and he’s never experienced anything like it. “I will tell you that I’ve been in River Falls for over 34 years and this is, certainly, the worst we’ve seen,” he says.

Laque says after the discovery the department was mobilizing a team to apprehend Schaffhausen when he walked into the department. He is currently being held in the St. Croix County Jail. A formal arraignment is scheduled for 1 p.m. Thursday.

Mike Brun in River Falls contributed to this story.