When police officers announced this year’s gun buy-back program would allow residents to exchange their guns for Wal-Mart gift certificates, they never expected a woman possessing a World War II-era Nazi Assault Rifle to take the bait.

But that’s exactly what happened in Hartford, Conn. over the weekend.

“It’s like finding the Babe Ruth of baseball cards. The rarity, it was made for such a very short period,” Officer John Cavanna, one of the two officers who discovered the gun, told ABC News.

Officer Lewis Crabtree added, “The chance to see a piece of history — this … is absolutely unbelievable.”

Cavanna and Crabtree are resident gun experts for the Hartford Police Department.

The woman found the weapon in a closet after her father, a World War II veteran, passed away. Her father had brought home the historic weapon, usually issued to SS troops, from Europe as a keepsake from the war.

She was unaware it is now valued between $20,000 to $25,000.

The Sturmgewehr 44, meaning “storm rifle,” dates back to 1944. Crabtree revealed it was the first “modern assault rifle ever made, eventually replaced by the AK 47 in 1947 by Russia, who copied the German design of the Sturmgewehr 44.”

And although every modern assault rifle is modeled after the Sturmgewehr 44, Crabtree understood how its significance could be overlooked.

“If you were to look at the gun and didn’t know anything about guns, you would think it was garbage,” Crabtree said.

In its current state, this Sturmgewehr 44 is inoperable. But in its prime, it would have held a 30-round magazine and shot 500 rounds per minute.

The gun buy-back program allows residents to anonymously turn in firearms to be destroyed. In exchange, the Hartford Police Department gives them a $50 or $100 gift card to Wal-Mart, depending on the type of weapon.

The Sturmgewehr 44 will have a different fate.

“We did not take the gun in for the gun buy-back program,” Crabtree said. “If we took it as part of the buy-back, we would have no choice but to destroy the gun. We don’t want to destroy that gun.”

The anonymous owner opted to keep the historic weapon at the police station until she is prepared to sell.

“It sounds like her family could use the money,” Cavanna said.

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