Background Check
It is said the person who set off the explosion at the dining hall a couple of days ago wore an Iraqi uniform.

The torso found at the scene of Tuesday's blast at a U.S. military base in Mosul was wearing an Iraqi military uniform, and authorities believe it was the torso of the bomber, Lt. Col. Steven Boylan, spokesman for the U.S.-led Multi-National Forces in Baghdad, told CNN on Thursday. ... "We have had a suicide bomber apparently strap something to his body, ... and go into a dining hall," he said. "We know how difficult this is to prevent people bent on suicide and stopping them." Evidence at the blast site includes components normally associated with bombs. There was no physical evidence of a rocket or mortar, according to a military statement Wednesday. CNN

People complain about background checks. They are done for a reason.  It turns out one of the people killed in the bomb blast used to be a co-owner of a bar where a friend of mine works.