The passenger in the car driven by Colten Treu when it hit and killed three Girl Scouts and a mother has pleaded no contest to a charge connected to the case.
Treu is serving 54 years.
A Chippewa County Judge found John Stender Junior guilty of harboring or aiding a felon after the plea was entered Monday.
The Girl Scouts and the adult supervisor were picking up trash along a county road in Lake Hallie almost three years ago when they were killed.
Stender told investigators he and Treu were huffing a can of air duster when the car went into the ditch where the girls were working.
Stender will be sentenced in July.