It pays to be careful when you're packing a gun around the president, even if it's part of your job. A deputy sheriff who works in the Emporia, Virginia region found that out first-hand when she made her way as an attendee to the rope line, armed with her department-issued gun.
Sheriffs and police officers providing security when the president visits their towns are often armed, but Secret Service Spokesman Edwin Donovan says the deputy sheriff in this instance was not part of that security detail. She was in uniform and presumed to be working but then joined the crowd as an attendee.
Normally, attending as a civilian would be fine, but when you have a gun in your holster among a crowd just before the president arrives, that's not a good situation.
The Secret Service spotted the woman and pulled her aside, telling her she needed to secure her weapon. She did so and was allowed to return to the event unarmed.
It should be noted, that the Secret Service also does intense security sweeps prior to any presidential event and then screens each person individually beforehand.