Today, police announced in a statement that Commissioner Andrew Coster had met with Hall to apologise over the case.
“This week I met with Alan and his family and apologised on behalf of police for the shortcomings in our original investigation that led to his wrong conviction,” Coster said in the statement.
“I am grateful to Alan and his family, who have been a great support to him, for meeting with me and accepting our apology.
Easton, 52, and his two teenage sons were attacked in October 1985 by a bayonet-wielding home invader.
He was stabbed in his liver during the frenzied attack and died of blood loss after emergency services arrived on the scene.
The murder weapon and a woolly hat were all that was left at the scene by the killer, described to be a Māori man, tall and broad in stature.
Hall, who was later diagnosed with autism spectrum disorder, came to police attention two months later because he owned a bayonet and beanie similar to the ones found at the scene, and was walking in the area at the time of the attack.
The description of the attacker and key witness statements from a man who was in the area at the time were concealed by police, and a jury found Hall guilty of the murder in 1986.