Online shopping certainly has its perks, but it's always annoying when you don't get what you ordered -- especially when you were expecting a TV and wind up with an assault rifle, instead.

Seth Horvitz of Washington, DC recently ordered a flat-screen television from a third party through Amazon, but when he found a long, rectangular package in the hallway outside his apartment, he knew something was amiss.

Upon opening the box, he got quite a shock: it contained a Sig Sauer SIG716, an Army-style semi-automatic assault rifle.

Unsure of what to do, he called the cops. "[They] were a little confused at first, they've never seen anything quite like it," says Horvitz. "They just took my information and then said we'll handle this weapon because it's illegal to keep here. It's illegal to transport in a car, so it can't be returned."

Although the shipping label had his name and address, the invoice inside the box showed the intended recipient was actually a gun shop in Pennsylvania. Amazon said it wasn't involved with the shipment, but it's investigating nonetheless, especially because transporting a weapon across state lines is illegal in DC.

Caroline Brewer, spokesperson for the Brady Campaign to Prevent Gun Violence, said in a statement, "Clearly, it's a dangerous situation in America when assault weapons are so prevalent and can so easily end up in the wrong hands, especially given that the rifle was left on the doorstep. Thank goodness Mr. Horvitz and his wife alerted the Metropolitan police right away. This mishap could have led to another tragedy."

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