Career
He was selected as the best Finnish modern pentathlete of the year in 1952-1953 and 1955-1956. Since 1952 Mannonen worked at the Helsinki mounted police, becoming its head in 1971, and retiring in 1990.
He was selected as the best Finnish modern pentathlete of the year in 1952-1953 and 1955-1956. Since 1952 Mannonen worked at the Helsinki mounted police, becoming its head in 1971, and retiring in 1990.