All Napier gunman Jan Molenaar needed was a screwdriver and a saw to help build an illegal cache of modified weapons, a gun expert says.
Police found 18 firearms at Molenaar's Napier home and have not ruled out finding more.
Among his weapons were two sawn-off, pump-action shotguns, a former
Army issue SLR (self-loading rifle), a revolver, a folding stock mini-14 style assault rifle and an M14-style scoped assault rifle.
Wellington gun store owner John Howat said it appeared someone had converted most of Molenaar's guns into assault weapons.
"This is not a person who would be doing target shooting or hunting," he said. "His reasons for having them is something only he would have known but to me this is a cause for concern and extremely worrying."
Mr Howat said it would be impossible to buy most of Molenaar's guns in their current form at a gun store or sporting goods shop.
"The question I would ask is who is selling those stocks, those magazines and pistol grips? That is irresponsible."
He said anyone with a saw and a screwdriver could make the changes to these weapons.
"But the intent for you and I would most probably be quite different."
Both shotguns had been cut down "enormously" and were not only illegal but technically pistols under current gun laws.
The assault rifles, which can be bought in stores, had had their stocks changed and modified to allow a greater capacity magazine. Converted like this, the semi-automatic weapons are not approved for use in New Zealand.
"If he had an A-category licence he could have bought those shotguns ... you can buy those in shops but not like that," said Mr Howat.
Police are defending their processes in tracking down revoked and expired licence holders.
They said about 50,000 people failed to reapply for licences in 2002 after a change in 1992 from lifetime permits to 10-year licences.
Superintendent Tony McLeod, police national manager operations, said there were less than 1000 people nationwide whose 10-year licences had expired whom they could not find. He would not comment on how police missed Molenaar but believed police were doing well with the resources they have.
"I think the districts, particularly in relation to the people whose 10-year licences have lapsed now, are doing a very good job," he said.
He said a small number of unlicensed owners were picked up regularly through other inquiries and during the process of renewal of 10-year licences.
But Green MP Keith Locke said he was doubtful at the police's response.
He wants to know how many people were registered gun owners in 1992 compared with now and how many prosecutions and convictions there have been for being unregistered.
"Clearly there is room for doubt that they had really focused their minds on bringing down people who are not registered as firearms owners," he said.
Police Minister Judith Collins said police would next week start to look at what changes were needed.
She had discussed it with police and asked them to look into issues such as online sales and whether guns should be registered, rather than only owners.
"I'd like [police] to have a look at the processes and whether or not they're being abused.
"I would like to get the facts, get advice from the people most concerned about guns and what they can do - and that would have to be NZ Police - and come back to Parliament with any suggestions."
- ADDITIONAL REPORTING: Claire Trevett, NZPA
* Fact v Fiction
Details released by the police yesterday make it clear that the Weekend Herald's front-page report on Saturday was right.
Despite widespread claims in other media on Saturday morning that we were wrong and Jan Molenaar was still alive, it is clear that he died on Friday afternoon.
His last communications with his partner and brother were just after 1pm, and a single gunshot was heard at 1.28pm.
From that time there was no further sign of life from the house through phone contact or shooting. As the Herald correctly reported, the police believed him to be dead.
