Once upon a time, I worked for a local cop shop. They were (and still are) one of the largest law enforcement distributors in the Southeast, and if you see a cop in TN, MS or AL with a Glock in his holster, he got it through that particular shop.
Now, as a Glock distributor, we routinely sent T&E guns to police departments in the region. One day, I'm behind the counter when the FedEx guy comes in with a T&E return from the TN Law Enforcement Training Academy in Nashville. I take the Glock box out of the FedEx sleeve, drag the firearms log from its place underneath the counter, and prepare to check the gun back into our inventory.
I open the box...hmm, Glock 23. That's the most common compact cop gun in the country. Wonder why'd they want to T&E one of those? Anyway...I drop the magazine and put it down on the foam padding of the box. I rack the slide...and out of the ejection port sails a live round. I catch it just before it can bounce onto the glass counter (an amazing feat considering my usual lack of dexterity), and examine it.
Yep, one primed, unfired, ready-to-go round of .40S&W Remington Golden Saber, 155 grain bonded core brass-jacketed hollow point.
The magazine was empty, but whoever T&E'd the gun just plain forgot that he had chambered a live round, and they sent the gun back to our shop in ready-to-go-boom condition.
I did shudder a little at the thought that this gun came from a place that teaches cops about guns, and the next time someone told me that "only the police are trained enough to carry handguns", I had a new anecdote ready.
Gun safety, folks. It's very easy to get complacent about it, and that goes especially for folks who shoot and handle guns every day, much in the same way that a good percentage of traffic accidents on longer trips happens when you're almost home. Familiarity breeds overconfidence.
Take it from a guy who has a confirmed kill on a bedroom window and its attendant vinyl blinds because a few years back he practiced dry-firing his Savage with live ammo nearby. A .30-06 going off in a closed room is very loud, especially when you expected a "click" rather than a "boom".
Check the chamber, check the chamber, and then check the chamber again. Every time the gun leaves your hand, or comes back into your hand. In fact, smack everyone upside the head who tries to hand you a firearm with the action closed, and smack yourself upside the head every time you catch yourself starting to hand a gun to someone in that condition.