He enlisted as a Private in the 20th Battalion when the war broke out, received various NCO promotions until he became Battalion Scout Serjeant in 1915, something likely influenced by his fluency in German and French. He was granted a commission in May 1916 and returned to England in late June 1916 for Officer training and then was posted to the 39th Battalion. Due to heavy casualties sustained in the Ypres operations he was sent to France as a reinforcement with the 2nd Battalion where he was put in charge of the Scout Section. He served continuously until demobilization,
After the war he became a newspaperman and served on the editorial staff of the Halifax Herald in Nova Scotia then transferred to the Canadian Press in whose bureau he served in Montreal, New York, and Ottawa as a political correspondent.
Murray was recalled for service in World War 2 from the Reserve of Officers and appointed Chief Cable Censor for Canada with the rank of Lt-Col which was later broadened to that of Chief Telegraph Censor, an appointment which embraced jurisdiction over all electrical transmissions by submarine cable, external wireless, trans-oceanic radiophone and internal landlines.
He administered a complex structure of offices and their varied staff throughout Canada. Subsequently, he was appointed Director of Military Intelligence and Commandant of Canadian Intelligence Corps with the rank of full Colonel. These functions were performed until his demobilization from the Army in March 1946. In recognition for this service he received the Order of the British Empire (OBE).
Colonel Murray died on 2 August, 1956
Author of the book Five Nines and Whiz Bangs, published in 1937, which is a collection of WWI shorts; "The Epic of Vimy", 1937 which was about the pilgramage for the unveiling and deication of the Vimy War Memorial; "The History of the 2nd Battalion, (East. Ontario Regiment) Canadian Expeditionary Force in the Great War, 1914-1918", published in 1947. The war had delayed Murray's writing of the book as he wrote nothing during it.