A man detonated a vest laced with explosives in a crowd of new police recruits at a Tikrit police station Tuesday, killing 52 people and injuring 140. With U.S. troops expected to leave by the year's end, Iraq is trying to prove that it's able to protect itself without foreign help. An undetonated grenade was also found at the bloody scene. Mosques in the area used their loudspeakers to ask locals to donate blood to the victims of the bombing. A local councilman is claiming that al Qaeda is behind the attack.