He was shot by Hans Plüschke, a 23-year-old West German border guard. According to West German officials, Plüschke was returning fire after his patrol was shot at. The incident took place at Wiesenfeld on the East-West border in the East German province of Thuringia.
His death occurred along with the deaths of another four East German border troops in quite a short time.
Such incidents led to a very strained relationship between the two opposing sets of German border troops. This has been proposed as a contributory factor for the failure of East Berlin border guards to assist the mortally wounded Peter Fechter.
Fechter was shot while attempting to defect to West Berlin on August 17, 1962 and died after lying in no-man"s land for an hour, in full view of both sides. In 1998, Plüschke was fatally shot in his right eye, the same fatal wound Arnstadt had suffered.
His body was found by a motorist on the Bundesstraße B 84, 70 meters from his vehicle.