We've talked to Errol Morris about his investigative ardor in our previous conversations, and we've mentioned his decades-long delvings into the case of Jeffrey MacDonald, the Green Beret doctor serving life in prison for murdering his wife and children. This time we get into the details, working our way through the evidence and Morris's contention that MacDonald was railroaded. Morris says the investigation was bungled from the beginning (one forensic expert called it a "colossal clusterfuck"), and that MacDonald was the victim of a peremptory narrative that blinded the police, the courts and the public to many of the facts. Errol's new book "A Wilderness of Error: The Trials of Jeffrey MacDonald" isn't just a meticulous anatomy of a murder case, but a sobering reflection on our sometimes wayward truth-finding process and justice system.