He served as the ninth Chief Engraver of the United States Mint from 1948 until 1964.
Roberts is perhaps most famous for designing the obverse of the Kennedy Half Dollar.
At the Philadelphia Mint he was designing and engraving coins, and presidential and congressional medals.
During his career, he engraved medals for Dwight D. Eisenhower, John F. Kennedy, and Lyndon B.
Roberts appeared as himself on the April 20, 1964 episode of the CBS gameshow To Tell The Truth.