Raleigh, N.C. — In reporting our on concealed weapons permits, I ran across an interesting factoid.

Durham County is the only county (out of 100) in North Carolina where owners of handguns are supposed to register their firearms. A concealed weapons instructor asked me why this was. 

"It goes back to the 1930s," said Maj. Paul Martin with the Durham County sheriff's department. He said the law was passed following a series of violent incidents that involved "shot houses," places where people could get liquor on the cheap.

The law remains on the books despite later restrictions on counties passing such ordinances. 

Martin said the law applies to pistols, revolvers and certain types of machine guns. 

Durham County residents have 10 days from the purchase of a firearm to register it with the Clerk of Superior Court. 

"Don't bring it to the courthouse, please," Martin said. Firearms are not allowed in the courthouse, unless they belong to a law enforcement officer. Just bring a description and serial number. The clerk's office keeps the file by hand, he said. As for how it might -- or might not -- be used, Martin wouldn't elaborate.

This appears to be among those regulations that falls into the category of "blue laws," prohibitions and regulations from earlier eras that live on past their usefulness.