Mad River (Virgil Flowers Series #6) in Bloomington, MN

They were average kids looking for something to do.
Today they started killing people.
A modern-day Bonnie and Clyde are on the run through rural Minnesota—victim by victim they’re having the time of their lives. But when Bureau of Criminal Apprehension investigator Virgil Flowers joins the hunt for the thrill-hungry kids, things take a shocking detour.