The 51-year-old gunman at the centre of a two-day siege in Napier told police minutes before he shot himself that he wouldn't go to prison.
On 7 May last year, Jan Molenaar shot dead Senior Constable Len Snee, 53. He critically wounded two other officers and a friend who bought cannabis off him, before barricading himself in his house.
The next day he committed suicide.
Detective Superintendent Rod Drew told an inquest in Napier that police made nearly 300 phone calls to the gunman during the siege.
He says that during the last call Molenaar said repeatedly he didn't want to come out and spend 20 years sitting in prison.
Mr Drew says moments after the call finished, police near Molenaar's house heard a single shot from a low-calibre gun.
Earlier, a Department of Labour inspector criticised the way police carried out a drug search at Molenaar's home.
Paul West told the inquest on Wednesday that officers who carried out the search warrant contravened several police regulations.
The three officers were searching for drugs at Molenaar's house when he arrived home.
Mr West told the inquest the fact that the officers did not wear protective vests and that their drug search was casual suggests there may be a national problem with police.
But Superintendent Tony McLeod says that is not the case and the response by Molenaar was disporportionate to his drug offences.
Mr West recommends police headquarters consider reviewing the adequacy of their systems and their organisational culture in at least three areas.
Molenaar's notes made public
The contents of notes Molenaar wrote just before he died have been made public for the first time.
After Molenaar's former partner, Delwyn Keefe, gave evidence on Tuesday, Coroner David Crerar read out the two notes.
In one he said he was bad, he let everyone down and paid for his crime. The other, written specifically to Ms Keefe, said that he loved her, she was a loyal, faithful, good person and that he had done his best to make her happy.
