A man was today jailed for life with a minimum non-parole period of 18 years for the murder of two people in an Auckland city apartment complex last July.

Baseem Ridha Kadhim Abbad Almery, 31, had earlier pleaded guilty to the murders of David Roberts and Deni Rudiantonio at the Alpha Apartments building in Vogel Lane.

In the High Court at Auckland today Justice Rhys Harrison said the sentence reflected the brutality of the crime.

Mr Roberts, 43, from Wales, was the complex's property manager.

Mr Rudiantonio, 41, from Indonesia, was a friend of Mr Roberts.

The prosecution's summary of facts said Almery, an Iraqi, first assaulted his girlfriend after she told him she wanted to move out of the apartment they shared in the complex.

Almery stayed at a nearby hotel after the assault and went back to the complex on the morning of July 19.

He had with him a chef's knife with a 20cm blade.

When he asked a cleaner where the property manager lived, Mr Roberts' apartment was pointed out.

He knocked on the door. When Mr Roberts answered, Almery stabbed him 12 times in the neck and chest.

Mr Rudiantonio, who was in the bathroom, was stabbed 18 times, receiving injuries in the neck, chest and abdomen.

Almery then cleaned himself, changed his clothes and footwear, and left the apartment.

Using the master keys, he got into his girlfriend's 11th floor apartment, waking her in her bedroom.

He told her he was going to kill her, but having seen her "he couldn't do it".

He then made a phone call telling a close friend he had killed two people.

The friend alerted police, who arrived at the complex soon after.

Attempts to force entry to the apartment prompted Almery's girlfriend to open the door.

Police saw Almery holding the knife to himself and threatening to jump.

Police negotiators and the armed offenders squad were called and negotiations continued for 3-1/4 hours.

Almery threatened to stab himself and told negotiators he had gone to see Mr Roberts to get the key to his girlfriend's apartment.

In other unprompted comments, he said: "I just wanted to get in. I only took the knife to scare them. I didn't want to hurt them...it all went wrong."

Almery eventually put the knife in a plastic bucket and surrendered without incident.