Alan Hall was exonerated by the Supreme Court three decades after he was found guilty of murder. Photo / Greg BowkerAlan Hall was exonerated by the Supreme Court three decades after he was found guilty of murder. Photo / Greg Bowker

Two elderly former police officers are on trial in the High Court at Auckland accused of perverting the course of justice during the 1986 murder trial of Alan Hall. Photo / Dean PurcellTwo elderly former police officers are on trial in the High Court at Auckland accused of perverting the course of justice during the 1986 murder trial of Alan Hall. Photo / Dean Purcell

Crown prosecutor John Billington, KC. Photo / Dean PurcellCrown prosecutor John Billington, KC. Photo / Dean Purcell

Defence lawyer David Jones, KC. Photo / Dean PurcellDefence lawyer David Jones, KC. Photo / Dean Purcell