Wrongfully convicted man Arthur Allan Thomas says his Royal Pardon and compensation was partly a result of pressure from the media on the Government for a retrial.
The 78-year-old was one of a small group of protesters gathered outside Parliament on Tuesday in support of Scott Watson.
Watson is serving time in Rolleston Prison for the double murder of Ben Smart and Olivia Hope in Marlborough Sounds on New Year's Day 1998.
His father Chris said the gathering of protesters gave him hope that "it's not going to go away".
"We're still here, there's another generation that is worried about this.
"They were only knee high at the time.
"It's getting out on social media now which didn't exist then."
He said he'd spoken to Scott recently who was heartened by the protest.
"He likes the idea he's in there but not forgotten."
Chris Watson the likelihood of a retrial was "not a lot" but he was prepared to keep pushing.
"We may see a change, we're prepared to out-wait them.
"Of course there's Scott, he's my son and I'm doing it for him. But they offended me as well. They offended my sense of justice with this trumped-up case.
"Hopefully we'll someday see a politician with enough oomph behind them to actually do something rather than protect themselves and their reputations."
Mr Thomas said the piece of evidence that convinced the jury Watson was guilty was testimony from water taxi driver Guy Wallace that Watson was the last man he saw with Ben and Olivia.
The fact Mr Wallace no longer stood by that claim called for a retrial, Mr Thomas said.
He said media played a crucial part in informing the public and putting pressure on the Government.
"You people are very important, do you realise?
"Let the public know what's going on, then the public will get into the MPs and tell them to do something about it. That's what happened in my case."
His daughter Bridget Thomas said family members had to be strong and stay positive.
"I just feel for the family. They're so strong, and so lovely. They've got all these people behind them now."
Justice Minister Amy Adams did not address the protesters.