Police first heard that Napier siege gunman Jan Molenaar was selling drugs and stashing firearms at his property more than a decade before he opened fire on a mate and three policemen, killing one, a coroner's court was told yesterday.

The inquest, before coroner David Crerar in Napier, is hearing details of Molenaar's fatal shooting of Senior Constable Len Snee on May 7 last year and the gunman's suicide the next day.

The 51-year-old had taken exception to a drug warrant being executed, and after opening fire on the officers, locked himself in the house.

He continued to fire at police until 1.28pm the next day, when he shot himself in the head.

Detective Superintendent Rodney Drew - who led the investigation into the shootings - said that 10 days before the warrant was executed, Mr Snee had used the police database to research Molenaar and his address.

From it, he learned of intelligence dating from 1995 saying: "Info received by anon letter that drugs are being sold from 41 Chaucer Rd by Jan Molenaar, selling some to kids. Informant states that he also has guns which the informant believes are stolen."

Mr Drew said there was no indication on the database that any further action was taken. Any paper record held would have been destroyed by 2009.

The records also showed Molenaar had historic convictions, including for obscene language (1978), theft as a servant (1979) and reckless driving (1979 and 1983). Charges of common assault were dismissed in 1988.

However, Mr Drew said, Molenaar's history contained "nothing which would cause alarm" that was recorded or held.

"Certainly nothing relating to his current possession of firearms and explosives, his drug dealing or his mental state or intentions."

Mr Drew said he did not know if the information about Molenaar had been followed up.

"It was 15 years old, the records have been expunged. There was nothing in our system on whether it was or not."

Mr Snee had a week earlier discussed Molenaar's property with dog handler Senior Constable Grant Diver and Senior Constable John Bruce, during a regular meeting to share drug information.

Mr Bruce had previously smelled cannabis while off duty and walking past the house. Mr Snee had said he would follow up the matter with a view to executing a warrant.

On May 7, sometime after 9.17am, Mr Snee and Constable Bruce Miller drove to Molenaar's home and parked in the driveway.

Mr Diver parked his silver dog van - with his German shepherd Fi inside - on the street below the house, the court heard.

Molenaar was out walking his dog, and his partner Delwyn Keefe - who also gave evidence yesterday - answered the door to the trio.

Keefe told the officers of cannabis in the bedroom and basement.

Keefe - currently in jail for her part in Molenaar's drug operation - told the inquest she warned police that he would be "ropeable" on his return. He arrived home at that moment, and threatened the officers with a firearm.

"He said to the cops, 'Get the f***en hell out of my house," Keefe said. "I ran towards Jan with my hands in the air ... Then I said to the cops, 'Get out, 'cause you don't know him like I do'."

Keefe left the house with the three police and Molenaar's mate Len Holmwood, who had arrived at the home.

As they reached the roadside, Molenaar appeared on the veranda armed with a .223 rifle with telescopic sights. He fired two shots, one of which hit Mr Snee in the right side of the neck.

Mr Miller and Mr Diver began to run uphill to safety but each was shot.

Keefe ran back inside to shout at Molenaar. "I said to Jan, 'You shot a f***en cop'," she told the court. "He said: 'Bub, you go. It's over for me'."

Molenaar then walked down a flight of stairs to the road and fired another shot at Mr Snee, who was lying on his back. The round hit him in the left hip.

He then went to shoot at Mr Diver and Mr Miller, who were crawling to safety.

Mr Holmwood then struggled with Molenaar. Molenaar threw Mr Holmwood on the ground and fired two shots at him, the second hitting his left thigh.

"I began cussing Jan," Mr Holmwood said yesterday. "I was swearing at him for shooting me."

As the injured officers took cover, Mr Holmwood tried unsuccessfully to move Mr Snee, then called 111 on his cellphone.

Mr Holmwood was rescued soon after by armed offenders squad members.

Crown Solicitor Russell Collins asked Keefe how she knew Molenaar was going to be "ropeable". She replied: "I just did. Just like anyone would be who got home and saw police in their house, they'd be angry too. Nobody was listening. Why didn't they just go?"

Asked if Molenaar ever took drugs, she replied: "No ... he had the odd puff."

Keefe cried when shown photos of letters Molenaar had written in an address book before his death. She confirmed they were in his writing.

Mr Drew said Molenaar believed his home was being watched and told friends he was determined to "go out in blaze of glory" if police came to arrest him.

The inquest will continue today.

FINAL NOTES

I was bad

I pay 4 my crime

I let everyone down I no

JM

I love u Del

U R so loyal, faithful person

I did my best 2 make you happy

Love Janni Mo 4ever