The FBI took it upon itself to track the weapons involved in the Washington Navy Yard shooting, leaving out of the loop the federal law enforcement agency in charge of firearm enforcement.

FBI agents headed to the northern Virginia gun shop where Aaron Alexis purchased a Remington 870 Express shotgun, rather than relying on the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). The tactic surprised Mike Bouchard, a former ATF assistant director.

"I have never seen an instance where ATF had not been relied upon to trace the gun," Bouchard told CBS News.

By 6 p.m. on Sept. 16, the FBI released information about the shotgun to the media. At the same time, an ATF spokeswoman said the agency's gun trace had not been completed.