Sidney Nsubuga Enoch admitted in court in Mukono that he bludgeoned Kato with a hammer in January, but that he did so in reaction to a sexual advance.
Kato died while on his way to a hospital.
The murder provoked outrage in Europe and the United States, leading to calls for Kampala to legalize homosexuality.
Ugandan police claimed at the time Nsubuga was a known ‘thief’ who was acquainted with Kato and that the killing had no connection to gay rights.
Kato had been involved in a campaign against a government bill that proposed the death penalty for certain homosexual acts.
However, as in most African societies, homosexuality is illegal in Uganda and considered a grave sin in violation of both the precepts of Christianity and African culture. Just prior to Kato’s killing, he was ‘outed’ in a newspaper that revealed names and addresses (and photos) of dozens of Ugandan gays and lesbians under the headline “Hang Them.”
Following Kato’s death, Uganda’s parliament decided not to proceed with debating the anti-gay rights bill.
Last month, Uganda entered into a war of words with British Prime Minister David Cameron who warned that the UK would slash foreign aid to countries that would not legalize homosexuality. In response, john Nagenda, an adviser to Ugandan President Yoweri Museveni said Cameron had a bullying mentality and treating Ugandans like children.