A tip led investigators Tuesday to the damaged car in a parking lot near where the 17-year-old boy lives in Niles, Mich.
St. Joseph County crash team commander Tim Spencer said the teen admitted driving the car when it hit 49-year-old David Fordyce of South Bend late Monday. Fordyce was directing traffic away from the body of 43-year-old Michael Marks of South Bend along Indiana 933 just north of the city.
Authorities said the driver who hit Marks stopped at the scene.
Spencer said prosecutors will decide whether the teenager will face charges.