AllMovie

A simple man becomes bent on violent revenge in this thriller. John Kinsdale (George Kennedy) is an American who lives with his wife and three children in Naples, Italy, where he's employed by NATO as an electronics expert. Kinsdale and his good friend Mike McAllister (John Mills) are working to bring NATO's computer systems up to date, but Kinsdale loses all interest in his work when he comes home one evening to discover his wife and kids have been brutally murdered in their home. Emotionally devastated, Kinsdale has no idea why his family has been killed until Italian investigator Dr. Lupo (Raf Vallone) learns the Kinsdales were murdered by a band of radical terrorists who are targeting the families of Americans living in Europe until their jailed comrades are released from prison. Using his computer skills, Kinsdale sets out to find the terrorists who claimed the lives of his family, and will stop at nothing to get the justice he demands. Featuring a score by Ennio Morricone, The Human Factor was the final directorial credit for veteran filmmaker Edward Dmytryk.