In 1977, documentary filmmaker Arthur Dong was attacked by four youths who shouted anti-gay epithets at him as they beat him severely.
This incident led Dong to a long personal investigation of the reasoning and motivations behind gay bashing; this film was the culmination of Dong's study of homophobic violence, in which he interviews seven men convicted of murder in hate crimes against homosexuals as they try to explain why and how they did what they did.
The stories range from men who believed that gays were wealthy and weak, and therefore easy targets for robbery and murder, to others who are convinced that God has condemned homosexuals and that they were somehow doing the Lord's work.
Several other men said that their murders of gay men stemmed from shame and confusion over their own latent or active homosexual desires, and one man simply and chillingly states, I don't have any opinion whatsoever for homosexuals, except they oughta all be taken care of.
Licensed to Kill was voted Best Documentary at the 1997 Sundance Film Festival and was shown on PBS as part of their showcase for non-fiction films -- P.O.V.