Floral tributes are left on a bridge on

Floral tributes are left on a bridge on South Street in Egremont, Cumbria, on June 3, 2010, for a victim shot by lone gunman Derrick Bird on Wednesday. Friends and neighbours of Derrick Bird, who killed 12 people on a shooting spree in northern England, have expressed shock that a "normal bloke" could wreak such devastation. But there were reportedly some prior warnings of the killings, which media reports suggest could have been caused by a family feud or a row at work -- and which caused the normally composed Bird to explode. AFP PHOTO/ANDREW YATES (Photo credit should read ANDREW YATES/AFP via Getty Images)