 The Israeli Mossad suspected him of being the head of Black September in Rome, and put him on an assassination list after Black September's attack in Munich.When he returned to his apartment building on the night of 16 October 1972, he was killed by two Israeli agents who shot him 11 times.At the time, Zwaiter was the PLO representative in Italy, and while Israel privately claimed he was a member of Black September and was involved in a failed plot against an El Al airliner, members of the PLO have argued that he was in no way connected.