Matthew Mindler, a former child actor known for his role as River in "Our Idiot Brother," was found dead at age 19 Saturday in. Manor Township near Millersville University. A Hellertown native, Mindler was a first-year student at the university and was last seen leaving campus Aug. 24. The Lancaster County Coroner’s Office is investigating the cause of Mindler's death. Mindler also had roles in an episode of "As the World Turns" and the 2016 TV movie "Chad: An American Boy."