'' Killer Cop '' ( ) is a 1975 Italian poliziottesco-crime film directed in 1975 by Luciano Ercoli . The film 's plot reprises the very real Piazza Fontana bombing which happened in Milan in 1969 . The gun in the umbrella used in the movie is similar to a Bulgarian umbrella used at London in 1978 to kill Bulgarian dissident Georgi Markov . '' Killer Cop '' was shot in Milan . '' Killer Cop '' 's plot is influenced from the Piazza Fontana bombings . The funerals seen in the film on a television screen are actual footage of the funerals of the victims of the bombings
Piazza Fontana bombing
Piazza Fontana bombing
Killer Cop