Jerry Sauve, chief deputy in the Marinette County Sheriff's Department, said the alleged sexual assault might be related to the killings. He told The Milwaukee Journal Sentinel the suspect, Scott Johnson, might have been hiding in the area to see if his alleged victim brought police there.

Johnson allegedly fired at swimmers in the Menominee River. Bryan Mort, 19, of Iron Mountain, Mich.; Tiffany Pohlson, 17, of Norway, Mich.; and Anthony Spigarelli, 18, of Kingsford, Mich.; were killed and another man was wounded.

To complicate the investigation, Mort was killed on the Michigan side of the river, while the other victims were on the Wisconsin side. Johnson, who had not yet been formally charged Saturday, was being held in Marinette County.

The alleged rape victim told the Journal Sentinel she and Johnson met in a store late last year and had become friends.