It was 6.34pm on 12 December when Madelyn Train had the last contact she would ever have with the three people she considered her parents. Gareth Train texted her from his rural Queensland property saying people had been sent ‘to kill us’. By this stage, Nathaniel, Stacey and Gareth Train had shot dead constables Matthew Arnold and Rachel McCrow, and their neighbour, Alan Dare. By later that evening, the trio would also be dead. Today, Madelyn Train speaks to the Guardian’s Nino Bucci about the ‘evil’ actions of her parents and their spiral into the world of online rabbit holes and conspiracy theories