A Massachusetts police dog was digging in a snow bank early Saturday morning found what he was looking for: not only did police canine Ivan discover a stolen handgun, he fired it too.

Officers said nobody was harmed in the mishap, which took place in a residential neighborhood in Lawrence, Massachusetts. Police said they began pursuing a vehicle that sped away from the site of what sounded like a shooting.

Soon an officer noticed a man exit the car and bury something in the snow, at which point the vehicle was pulled over and backup was called. When Ivan and his handler, Lt. John Pickles, showed up, the canine began pawing at the snowbank indicating he'd found something.

Then, a shot rang out. Ivan apparently found the gun and discharged it with his paw on accident, giving police quite a scare.

The three men in the vehicle were all arrested. The gun, a semiautomatic Ruger, turned out to have been stolen and had its serial number filed off.

While canines firing weapons is incredibly rare, this is not the only story of a dog discharging a gun in recent weeks. Police in Sebring, Florida said last week that a dog knocked a loaded handgun onto the floor of his owner's truck, causing the weapon to fire and hit the man's leg. The driver of the vehicle later told police he thought the gun was not loaded.

This video is from CBS Boston, aired Monday, March 4, 2013.