A judge in Australia has taken the unusual step of releasing shocking footage of the moment police captured a 17-year-old gunman.A gun-wielding teenage boy who was high on a cocktail of drink and drugs when he shot an 18-year-old dead has been jailed for at least 24 years.In a rare move at the sentencing hearing in Adelaide, Australia, the judge allowed Liam Humbles to be named, as well as allowing shocking video taken at the time of his arrest to be released.The disturbing police video shows the shirtless Humbles face down on the bonnet of a police car, barely coherent as he answers questions from an officer.A second video shows the teenager in a police interview room staring at the floor as a police officer reads to him the reasons for his arrest and the charges being put to himHumbles had previously been found guilty of murdering Lewis McPherson, 18, and the attempted murder of Liam Trewartha and James Lamont.