Honolulu police are taking a close look at the gun used in the weekend’s fatal shooting at Ala Moana Center.

It was not registered to the suspect — nor — apparently — to anyone else.

Un-registered, un-traceable guns are a large and growing problem for law enforcement agencies across the mainland.

The apparent discovery that the gun in this weekend’s shooting is one of those — could signal a worrisome development in hawaii.

Court documents show that the officer who found shooting suspect Kapono Miranda — recognized the handgun as being un-serialized.

They’re also referred to as home-made guns — or ghost guns.

many of them start as what are called 80-percents — and many of them are purchased online — legally.

Tom Tomimbang, an owner of 808 Gun Club says, “It’s not illegal in Hawaii to have an 80 percent or bring in an 80 percent, into the state, but once you start modifying it or altering it, so that it cane become a firearm, then you have to register it. And if you get caught, without it being registered, you can get arrested.”

As part of its investigation, HPD ran a check on Miranda.

Miranda did not have a permit to carry a gun — and had no firearms registered to his name.

Tom Tomimbang is an owner of 808 Gun Club — but also draws his expertise in gun laws from a career in the Honolulu Police Department. he’s now retired.

The shop does not sell 80-percents.

It does sell parts that do-it-yourselfers, or hobbyists — can assemble from pieces like this — which are legally considered firearms.

Items like that in the shop — have serial numbers.

80-percent pieces require kits — usually sold by the same manufacturer — to turn them into live-fire guns.

Tomimbang says, “To complete a firearm, so that the last 20 percent is not something a novice should be doing, first of all, because it could be unsafe. But there are a lot of firearm enthusiasts, or hobbyists that want to try to do their own.”

We spoke with State Senator Clarence Nishihara — who is traveling — and he said the ghost-gun matter is definitely worth further research and discussion with law enforcement.