High Quality Content by WIKIPEDIA articles! Colonel Walter Rudolph Walsh (born May 4, 1907) is a former FBI agent, USMC shooting instructor and Olympic shooter. Walsh joined the FBI in 1934, serving during the Public enemy era, and was involved in several high-profile FBI cases, including the capture of Arthur Barker and the killing of Al Brady. He served in the Pacific theatre during World War II with the Marine Corps and, after a brief return to the FBI, served as a shooting instructor with the Marine Corps until his retirement in the 1970s.