BOSTON UPDATE: Another Tsarnaev Friend Arrested, Another Government Leak

Reading Time: 2 minutes Stephen Silva, a friend of accused Boston Marathon Bomber Dzhokhar Tsarnaev, pleaded not guilty to federal drug and gun charges. Publicly, the authorities say his arrest has nothing to do with the Boston Marathon bombing. So why are anonymous law enforcement sources saying Silva had the pistol Tsarnaev and his brother used to murder a police officer and shoot at others?