A Queensland coroner is investigating the motivations of Gareth, Nathaniel and Stacey Train, who killed constables Matthew Arnold and Rachel McCrow and a neighbour, Alan Dare, at their remote property in Wieambilla. So far, the testimonies have included a forensic psychiatrist and an extremism academic. Queensland state reporter Andrew Messenger speaks to Tamsin Rose about the recommendations that have been made by police and experts to prevent a repeat of this tragedy You can support the Guardian and the Full Story podcast here