According to his attestation papers dated March 7, 1916 at New Toronto, Frederick Mitchell of Church Street (present day Royal York Road), Mimico was born on November 12, 1893 in Toronto. He listed his father, Harry D. Mitchell, 37 Mercer Street, Toronto as his next of kin. He listed his occupation as teamster. He indicated that he was an active member of the 12th Regiment, York Rangers. He was 22 years of age and stood 5 feet 10 inches tall. He had blue eyes, black hair and a dark complexion. He was a member of the Church of England.
In the 1914 Toronto City directory he was boarding at the home of Joseph Johnson on the west side of Louisa Street.