The New Zealander was convicted of the murder in 1994 of his parents Margaret and Robin Bain and siblings, Arawa, Laniet and Stephen at their Dunedin home. He was then acquitted in a retrial in 2009 after serving 13 years in jail.
The conference in Perth was billed as a world-first gathering of forensic experts, lawyers and justice advocates.
He told his story alongside his long-time supporter, Joe Karam.
Bain said addressing the conference with his long time supporter and advocate Joe Karam would probably be his last public speech.
"At this point in time, it's a one off. I was invited nearly two years ago and I read up about it and it was an opportunity to speak amongst a group of people that share the same opinions and challenges that Joe faced."
Read the full exclusive post-conference interview with David Bain in tomorrow's Herald on Sunday.