Police in Kansas arrested a 15-year-old boy late Friday who allegedly shot and killed his parents before fatally shooting his girlfriend's grandfather.

Authorities began looking for Dylan Shanks after he allegedly killed the grandfather and wounded his girlfriend's grandmother at their Tulsa home. The grandmother, shot in the shoulder, was treated and released.Shanks disappeared in a car after leaving the grandparents' house, authorities said. They went to look for him at his home in rural Glenpool and discovered the bodies of his parents.