The next time a big public event in Alabama goes off without a hitch, some of the credit might go to Derby, a 64-pound bundle of energetic, smiling, food-driven yellow Lab.

And if the worst happens, Derby — a trained explosives detection K-9 based at the Bureau of Alcohol, Tobacco, Firearms and Explosives’ National Center for Explosives Training and Research at Redstone Arsenal — might get called into the investigation.

The 22-month-old Labrador retriever graduated in July from the ATF’s National K-9 Academy in Front Royal, Va., as part of the newest class of Search-Enhanced Evidence K-9’s – highly trained dogs who work off-leash. Her badge number is appropriate: 205, like Birmingham’s area code.