Colorado-based Biofire Tech is taking orders for a smart gun enabled by facial-recognition technology, the latest development in personalised weapons that can only be fired by verified users.

But in a sign of the long, challenging road that smart guns have faced, a prototype twice failed to fire when demonstrated for Reuters this week.

Company founder and Chief Executive Kai Kloepfer said the software and electronics have been fully tested, and the failure was related to the mechanical gun which was made from pre-production and prototype parts.

At other times during the demonstration the weapon fired successfully and the facial-recognition technology appeared to function.

Biofire’s gun can also be enabled by a fingerprint reader, one of several smart gun features designed to avoid accidental shootings by children, reduce suicides, protect police from gun grabs, or render lost and stolen guns useless.

The first consumer-ready versions of the 9mm handgun could be shipped to customers who pre-ordered as soon as the fourth quarter of this year, with the standard $1,499 model possibly available by the second quarter of 2024, Biofire said.

That could make it the first commercially available smart gun in the United States since the Armatix briefly went on sale in 2014.

At least two other American companies, LodeStar Works and Free State Firearms, are also attempting to get a smart gun to market.

In a demonstration at Biofire headquarters in Broomfield, Colorado, Kloepfer initially fired a round without issue and set the gun down. Then another man tried to shoot but was unable to because the gun did not recognise his face.

Kloepfer then came back to fire it again. It was at that point the gun unexpectedly went click on two occasions, though it did fire on subsequent trigger pulls.

Then another prototype was brought in and that weapon functioned as planned.

Many gun enthusiasts have become skeptical of smart gun technology, concerned it will fail when a weapon is needed for self-defense at a moment’s notice.

“I’ve not just built a product, but an entire company around: How do we build an extremely reliable product that will always unlock for you anytime that you pick it up, and will never unlock when your kid finds it,” Kloepfer said.