He joined the Royal Navy Fleet Air Arm, served overseas during the last year of the Second World War.
Simmonds joined the Royal Canadian Mounted Police on April 23, 1947, where he trained at “Depot” Division in Regina.
In 1966 he moved to Burnaby, British Columbia as Sub-Inspector, but transferred to Victoria in 1971 to work in the staffing and personnel department.
Heavily active during his term as Commissioner, Simmonds was named Vice President of the International Criminal Police Organization (Interpol), as well as the Dominion of Canada Rifle Association.
After retiring in 1987, he negotiated peace between warring tribes in South Africa and became the senior law enforcement officer of the United Nations Fund for Drug Abuse Control (UNFDAC) in Vienna.