Walsh died yesterday, six days before his 107th birthday at his home in Arlington, USA Shooting announced.
Walsh, who first honed his shooting skills by picking off clothespins on a clothesline with a BB gun as a child, finished 12th in the men's 50-metre free pistol at the 1948 London Olympics. He was 41 by then, and had already demonstrated his marksmanship with the FBI and the Marine Corps.
During the Depression, Walsh was instrumental in the capture and killing of several gangsters. As an FBI rookie, he discovered the body of Baby Face Nelson after a shootout that left two federal agents dead, and a year later helped catch Arthur (Doc) Barker of the Barker Gang.
Walsh took a commission as a second lieutenant in the Marine Corps in 1938 and went on active duty in 1942, eventually serving on the front lines in the First Marine Division, and spent more than 20 years as a shooting instructor for the Marines after the war before his retirement in 1970.
Born in Hoboken, New Jersey, on May 4, 1907, Walsh was married for 43 years until his wife died in 1980.