Those who knew Derrick Bird speak out about the Cumbrian killer, who shot his brother and 23 others in a shooting spree lasting several hours before turning the gun on himself. Richard Bilton reports on the events of Wednesday 2nd June 2010 with first hand accounts from eyewitnesses, emergency teams and survivors. What made Derrick Bird switch from quiet cabbie to gun toting psychopath and were any warning signs missed?