Former soldier admits to leaving guns at the home of Northland shooter Quinn Patterson

Newshub can reveal a former landmine disposal expert and soldier has pleaded guilty to unlawful possession of firearms and supplying firearms to Whangarei gunman Quinn Patterson.

Michael John Hayes used to work for Patterson - the man who killed mother and daughter property inspectors Wendy Campbell-Rodgers and Natanya Campbell.

The pair were inspecting Patterson's rented house on July 26, 2017 when he shot them.  He was later found dead in his burnt out house.

A former soldier and humanitarian with no previous convictions, Hayes was in the dock on Friday and admitted all nine charges against him.

Hayes, 62, spent time in the New Zealand and Australian military and more recently had a long career as a landmine and combat engineer in places like Iraq, Angola and Cambodia.

While charged with "supplying" guns to Patterson, the charge relates to Hayes leaving some of his firearms at Patterson's place after the pair did some target practice. Hayes was Patterson's friend and employee.

"There is certainly no suggestion he left the guns for this man to commit a homicide," his lawyer, Arthur Fairley, said.

This is how it all fell apart for Hayes.

After returning from bomb disposal duty overseas in 2013, he met Patterson who asked him to do some possum trapping at his rural property. Patterson eventually employed Hayes to help him with his maintenance company.

"He trusted Mr Patterson," Mr Fairley said.

But that trust was seriously misplaced. Hayes was a licenced gun owner - Patterson was not.

Before the shootings occurred, Hayes his son and brother in law came to Patterson's place to do some clay bird shooting.

Hayes was then called away to a family emergency concerning his elderly father. He decided he'd leave his guns at Patterson's place - he locked them in a cabinet in a shed at the property and said he'd be back to get them.

"He did shooting up there and he was going to go back and do shooting on other occasions. So he should not have left the guns there," Mr Fairley said.

"It was a lapse of judgement, that's why my client has pleaded guilty."

The five guns Hayes left at Patterson's property included a included a Saiga 7.62 military style semi-automatic and a modified Saiga shotgun.

But on top of that, Patterson had been illegally amassing his own stash.

"Police found about 15 or 16 firearms at the scene - something in that order," Mr Fairley said.

He says there's no evidence Hayes' gun was that one that fired the fatal shots.

"The Crown are not advancing as an aggravating factor that the death weapon is attributable to my client," he said.

As well as the supply charges, Hayes has also pleaded guilty to multiple charges of unlawful possession of firearms after he modified some of his weapons which made them an E category gun or a military-style semi automatic.

Hayes did not have a E category licence.

Police had been to Patterson's place in the weeks before the Ms Campbell-Rodgers
and Ms Campbell were killed, and contractor Jeff Pipe was shot.

That was in response to a complaint about Patterson's homemade shooting range - but police decided it was a tenancy issue and no further action was taken.