Robert Duvall was 30 in To Kill a Mockingbird when he played the character 'Boo Radley'.
That was over 61 years ago in 1962.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 93, and has starred in 124 movies in total, 122 of those since To Kill a Mockingbird was released.
In To Kill a Mockingbird, I think Robert Duvall looks: