Dallas police reveal details of bomb-carrying robot it used as 'last resort'

Gunman Micah Johnson was killed using a Northrop Grumman tactical robot carrying one pound of C4 explosive in its arm following gun battle The Dallas police department has defended its decision to use a robot to kill the gunman who fatally shot five of its officers, saying the controversial method was used only "as a last resort". Amid disquiet about the potential legal implications of the killing, the department also gave the first public details of the model of robot and type of explosive devi...