1Trial and Error Ten years ago, New Zealand’s best known ex-prisoner was released on full pardon. It took Arthur Alan Thomas nine years to win the fight against his conviction for the Crewe murders. In the Thomas case, the police gathered crucial evidence from interviews and investigations, then withheld much of it from Thomas’ Defence Council. Ten years on, discovery, or the convention which says Prosecution should hand over all relevant evidence, is yet again at the centre of pleas by two people now in jail for crimes they say they did not commit.