Key Points:

The dismissal of charges against an Auckland gun-shop owner who opened fire on a machete-wielding robber is not an invitation to other shopkeepers to take up arms against intruders, police warn.

"There will be people who take from [yesterday's] decision the message that it's okay to arm yourself against the possibility of attack," spokeswoman Noreen Hegarty said yesterday.

"The dismissal of the charges should not be seen to carry the message that people in business, or anywhere, should have weapons at the ready for self-defence."

Her comments come after two justices of the peace threw out a charge of illegal possession of a pistol against Auckland gunstore owner Greg Carvell, ruling the Crown failed to prove a prima facie case.

Mr Carvell was charged after shooting armed intruder Ricky Beckham in the stomach with a .45-calibre pistol after Beckham entered his Small Arms International gunshop in Great South Rd, Penrose, demanding guns and threatening staff with a machete.

Police later decided not to charge Mr Carvell for the July 27, 2006, shooting, but laid a charge of possession of a pistol for unlawful purposes.

But the JPs yesterday ruled that prosecutors had failed to prove the pistol was kept for anything other than a lawful purpose.

Mr Carvell said he was overwhelmed and ecstatic, and looking forward to getting on with his life.

"It has been a very long year, very stressful ... It's over now."

Mr Carvell was unrepentant about his actions, claiming he and others would have been killed if Beckham had not been stopped. He had only attempted to protect himself and others, and the Crown had failed to prove any criminal intent.

"Once you have got the keys out of my pocket when I am dead, you can have what you want."

Mr Carvell said "some" people might believe the JPs' ruling made it okay for others to keep a loaded weapon for protection, though his pistol was not fully loaded at the time.

A magazine was partially in place, and the weapon had to be cocked.

He was also asked if all shop owners should have an all-but-loaded gun as protection.

"Yeah, gunshops. But I don't think other people can't have the right to defend themselves. Why would it be unlawful if they had a stick behind the counter?" Mr Carvell asked.

He would not say if he still kept a firearm behind the counter.

Crown Solicitor Simon Moore said he would be taking advice from police, prosecutors and Crown Law before deciding the prosecution's next move in the matter - though "public interest factors" would determine any future court action.

Crown prosecutors had three choices in fighting the Carvell decision: laying the charges again, seeking a judicial review of the JPs' ruling, or appealing to the High Court.

Mr Moore refused to comment on the JPs' decision, but said he was personally "generally in favour of this type of thing going to a jury".

Mr Carvell's wife, Nicola, said she hoped the case would send the message that it was okay to defend yourself with "a gun, a baseball bat or anything".

"Hopefully, this will set a precedent that it is okay to use your right in self-defence," she said.

However, she did not believe the average dairy owner would use a gun in self-defence.

Mr Carvell had some high-powered legal support from early in the court process.

At Beckham's High Court sentencing in February, Justice Rhys Harrison repeatedly said he was worried that Mr Carvell had defended himself against an armed intruder, only to be hit with firearms charges.

Mr Carvell said he would discuss with his lawyer Greg King whether to seek costs.