Katz was involved in a criminal-libel in Italy over the contents of his book Death in Rome, in which he was charged with "defaming the memory of the Pope" Pius XII regarding the Ardeatine Massacre of 335 Italians, including 70 Jews, at the Ardeatine Caves in 1944. The case ended with the charges being dismissed in 1980 by Italy's highest court. The suit had been issued by the Pope's family.[5][6] The book was made into the 1973 film Massacre in Rome.