He rode a specially trained "falling" horse named Cocaine.
Though having minor roles in several films, Shock Corridor (1963) turned out to be his biggest one, as he played Wilkes, the villain/head hospital attendant.
Had a reputation for having a rowdy persona and was nicknamed "Bad Chuck". Ironically, fellow stuntman Chuck Hayward was nicknamed "Good Chuck", as he was the exact opposite of Roberson.