Reuters

Eduardo Sencion is shown in this driver's license photograph. Authorities say he opened fire with an AK-47 in Carson City before killing himself.

By Pete Williams, NBC News chief justice correspondent

The assault rifle used in the deadly shooting at a Nevada IHOP restaurant came from a Chinese company whose weapons imports have been banned since 1994, authorities say, but it’s unclear how the gunman acquired the AK-47 rifle.

Law enforcement officials say the man who fired the shots Tuesday in Carson City, Eduardo Sencion, had three weapons: two AK-47-style rifles and a handgun.

The officials say the actual shooting was committed with a Norinco Arms AK-47. Norinco, the Chinese company, is a global supplier of firearms and military weapons.

Since 1994, the United States has banned all imports of Norinco weapons into the United States (other than shotguns), but dealers were allowed to sell any stock they acquired before the import ban went into effect.

An attempt to trace where and how Sencion acquired the weapon has not come up with an answer. The dealer who originally sold the weapon has since gone out of business, which complicates the tracing effort.

Nevada IHOP shooter was 'gentle, kind man'

The gun could have been legally purchased. It could have been imported before the Norinco ban. The Clinton-era assault weapons ban applied to weapons like it, but the law expired in 2004. When Barack Obama first came into office, the administration suggested it would ask Congress to reimpose the ban, but that idea was quickly abandoned. 

Officials say Sencion had two other weapons with him, apparently in the van he drove to the restaurant — a handgun and a second AK-47. The other AK-47 was a Romarm Cugir, made by a Romanian weapons company. The handgun was a Colt .38 revolver.