Investigators in Washington and Boston denied Wednesday that an arrest had been made in the bombing of the Boston Marathon. They had earlier said there was "substantial" progress in the case.
One Boston survivor of the bombings at the Boston Marathon described the harrowing moments near the finish line, and the second blast as 'a horrific scene."
A second letter sent to the U.S. Senate and another intended for President Obama have potentially positive for the lethal poison ricin. The law enforcement official said the letter is similar to one recently mailed to Mississippi Senator Roger Wicker on Tuesday. Capitol police, the FBI and other agencies have continued an investigation
The Boston Marathon bomber used a pair of six-liter pressure cookers packed with metal nails and ball bearings as a means to kill his victims at the finish line during the Boston Marathon
