Tucson gunman may not have acted alone: Sheriff

"TUCSON, ARIZONA: Police believe that the gunman who shot a US congresswoman in an attack which left six dead in Tucson, Arizona did not act alone, the local sheriff said. 

"There's some reason to believe that he came to this location with another individual," said Clarence Dupnik, sheriff of Pima County who is in charge of the probe into the attack on Representative Gabrielle Giffords. 

Giving an update on the shooting, he said the 22-year-old man gunman, who was arrested at the scene, "has kind of a troubled past, and we're not convinced that he acted alone." 

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