When a man was bashed and died in his Maryborough church grounds in 2008, Catholic priest Father Paul Kelly could not simply stand by.
The men who killed Wayne Ruks were convicted of manslaughter rather than murder when the "gay panic" defence was invoked.
The partial defence has been used by people accused of murder to claim they were provoked due to an unwanted sexual advance.
As a Catholic priest, Father Kelly may seem an unlikely ally in the gay rights movement.
But he was disgusted by the case, starting a Change.org petition that has almost 290,000 signatures, making it one of the biggest the website has hosted.
Finally this week, Father Kelly's long campaign paid dividends, with the Queensland government introducing a bill to abolish the partial defence.
"The more I thought about it [Wayne Ruks' case], I thought, this doesn't make any sense," Father Kelly said.
"It got me fired up. I realised that this really was a terrible loophole and should be closed."
Father Kelly said he wrote to the Labor government at the time and was not satisfied with the response, so decided to start his petition.
He said the issue was one of basic human rights, and he was inspired by his faith.
"This is actually the first and most fundamental human right that people, irrespective of gender, sexuality, race, all have the same protection from violence and killing under the law, and there's no exceptions based on those qualities," Father Kelly said.
"I came from a very strong belief in the absolute dignity of all human life and every single person is worthy of respect and safety and dignity."
Father Kelly said over the years, he was at times made to feel like a fool, but he kept up the fight in between services, baptisms, weddings, funerals and visiting the sick and dying.
"There was a lot of attention and at one point, I thought jeez, this is stressful, I felt like crawling under a rock and going away," he said.
"It was worth it for the issue. But I thought, I don't know how you can keep going.
"I thought, I'd like to drop it and get out of the limelight, but it would have meant giving up on the best chance of actually getting this dealt with, so I just persevered.
"It's all been worth it."
Father Kelly, now leading a parish on the Gold Coast, said he was very heartened that 290,000 people thought the law needed to be changed and signed his petition.
"But I thought 12 people should have been able to say, hey, this is crazy and reasonable people could say, you're right, let's not wait for another 180,000, let's just change it," he said.
"I'm not sure what the delay was, but I'm glad that it has changed."
Queensland and South Australia are the only jurisdictions in Australia not to have repealed the gay panic defence.
The successful application of section 304 of the Criminal Code (killing on provocation) reduced the criminal responsibility to manslaughter, meaning the defendant avoided life in jail.
In November, a string of celebrities banded together to urge the Queensland government to introduce the reforms before the end of 2016.
Ms D'Ath had flagged the legislation would be introduced to parliament later in 2016 in May.