The shooting deaths of six people including two Queensland police at a rural property two months ago was the nation's first domestic terror attack inspired by "Christian extremist ideology", with a US man a person of interest in the case.
Constables Matthew Arnold and Rachel McCrow were shot dead by Nathaniel, Gareth and Stacey Train after the officers arrived at their Wieambilla property, more than 300km west of Brisbane, on December 12.
Alan Dare was also gunned down after going to check on the commotion, with the Trains killed in a gunfight with specialist police later that night.
