Authorities say the 24-year-old man from Park City, Ill., was arrested Thursday after Rock County sheriff's authorities got a tip about the suspect vehicle.
The Beloit Daily News reports the tip described an Infiniti SUV with front-end damage.
Twenty-four-year-old Mitchell Vance and 18-year-old Devin Julius, both of Janesville, were killed in the crash on Highway 14 in the Town of Harmony on Sunday. Julius was originally from Freedom. The two were riding motorcycles when an SUV crossed the center line and hit them. Other motorcyclists were able to avoid the crash.
Sheriff Robert Spoden says the suspect is in jail in Illinois awaiting extradition.