Kevin Henry - also known as Curtain - was charged with the murder of a 36-year-old Aboriginal woman named Lynda, whose body was found on the banks of the Fitzroy River in 1991.
But a growing number of people say he was wrongfully convicted, and are calling for his release.
"Today is a fighting chance for justice for this young boy to walk free in the community," Kevin's sister-in-law Kym Henry told NITV News.
The case of Kevin Henry has recently become the subject of a powerful podcast series by journalist Amy McQuire and Martin Hodgson, a senior advocate for the Foreign Prisoner Support Service.
The police investigation was conducted two years after the Fitzgerald Inquiry, which revealed widespread corruption amongst Queensland police.
Mr Henry's supporters say the investigation was seriously flawed, as it didn't include any forensic evidence and it's based on what they say was a 'coerced confession'.
"What happened here on these grounds should never have happened, but it did, and it was covered up," Kevin's cousin Douglas Graham told the crowd at today's rally.
His lawyers have already exhausted all avenues for appeal, but there are calls for Kevin to be immediately released on parole, with an official pardon.
Amongst today's supporters was Lex Wotton, who was formerly incarcerated for inciting the so-called Palm Island riots, following the death in custody of Mulrunji Doomadgee, before going on to win a landmark court case which found the Queensland Police Service had been racist in their response to the unrest.
Mr Wotton spoke to Mr Henry via phone this morning, to reassure him that "truth and justice" would prevail.
"For 25 years he probably felt like no one was listening, and now today as I said to him, your voice will be heard," he told NITV News.
"I hope everything will go in Kevin’s favour, he will be acquitted of all charges and stuff and then he will get the support upon release to support him in whatever way for him to fit back into society and his own community.
"He needs to just hang out a bit more until the legal process takes shape."
The decision to exonerate Kevin Henry lies with Queensland Attorney-General Yvette D'Ath and Governor Paul De Jersey.