This is probably the most comprehensive and authoritative overview of this most perplexing murder, which took place in 1970. Arthur Allen Thomas was notoriously tried twice, found guilty both times despite very shonky evidence, then finally pardoned. The murders have never been solved. This account by an investigative journalist and an associate professor of journalism, looks at the entire case, reviews all the evidence, interviews many surviving witnesses, and presents some new information. It's compellingly written, persuasive and convincing. Despite this being, I think, the 10th book on the subject, it still demands to be read for the full picture. It's also a social history of New Zealand in the 1970s and since. A fascinating and vital book.