On June 14, 1951, Corporal Arthur M. Diffendale, 33, was shot and killed during a traffic stop on the Winnie Hill Road near the city of Oneonta. Witnesses said as Corporal Diffendale approached the vehicle, the driver exited the truck with a rifle and shot Corporal Diffendale. He died as a result of a chest wound while en-route to the hospital. An investigation revealed the truck, license plates and cattle being transported were stolen. The suspect was captured, convicted and sentenced to a term of life imprisonment. He was paroled and subsequently arrested by another Trooper for illegal possession of a handgun.
Corporal Diffendale enlisted in Troop K on July 1, 1940, and was granted a Military Leave of Absence during World War II. He returned to the State Police on November 16, 1945.