Police Commissioner Charles Ramsey said that an audit of one of the department's main gun storage units has revealed that an M-16 rifle is missing.
The regularly-scheduled audit was conducted last week of 1,356 M-16s the department received from the federal government in 2009. Those weapons are held in crates in large vault at the department's training academy, Ramsey said. Only "a couple" of people have the access code to the vault, which is also locked with a deadbolt, he said.
"It was either taken or there was an inventory error to begin with," Ramsey said.
Ramsey said he has notified the FBI and the Bureau of Alcohol, Tobacco and Firearms about the missing weapon. The last audit of the guns was conducted in December and everything was accounted for then.