Leigh Cleveland, left, and Peggy Noble died in the Ashburton Work and Income shootings on September 1, 2014.

Ashburton Work and Income shooter has been jailed for at least 27 years – one of the longest sentences imposed in New Zealand.

Justice Cameron Mander described Tully at the sentencing in the High Court at Christchurch as "a very dangerous man".

The shootings were cold-blooded executions. The lethal attack on people doing their job was callous and brutal. The staff were vulnerable and defenceless.

ALDEN WILLIAMS/Stuff.co.nz Deputy Chief Executive of the Ministry of Social Development, Carl Crafar outside Christchurch High Court following Russell John Tully's sentencing on Friday.

The loss and harm was "incalculable".

READ MORE:

* Images of Ashburton Work and Income shooting revealed

* Russell John Tully went from nicest bloke to killer

* Winz shooter found guilty

Judge Mander said there would likely have been more fatalities at the office on September 1, 2014, if other staff had not fled or been away from work.

Dean Kozanic Winz worker Leigh-Anne Hydes told Tully he was "an evil man". She was later diagnosed with post-traumatic stress disorder.

Tully disguised himself and went to the office with a shotgun intending to shoot staff for a sense of grievance thinking he was unfairly treated over several months.

He had been trespassed from the office.

Before moving to Ashburton, Tully used methamphetamine, cannabis, synthetic cannabis and drank a lot of alcohol.

Dean Kozanic Kim Adams, left, was shot at as she tried to escape. Alison Kermode also gave a victim impact statement.

Justice Mander said Tully's claims in court – that the Crown's evidence and other reports were a "cover up" – showed he "didn't much care" about his victims.

He said Tully had considerable intelligence. He had limited mental health issues and unusual personality traits. He was a high risk of harming others, as he had no regard for the sanctity of human life. His prognosis for rehabilitation was poor.

Tully's term is the third longest term on record in New Zealand, behind triple-murderer William Bell and double-murderer Bruce Howse.

The Crown had sought a 33-year minimum non-parole term.

Tully, 49, was convicted at a trial of the shotgun murders of Winz receptionist Peggy Turuhira Noble and case worker Susan Leigh Cleveland.

He was convicted of the attempted murder of Kim Elizabeth Adams, who he fired at with the shotgun but missed as she escaped out a back door to the offices.

He was found not guilty of attempting to murder Lindy Curtis, who he shot in the thigh.

The police manhunt found him hiding in a hedge near Ashburton on the day of the killings.

AN 'EVIL MAN'

Winz worker Kim Adams, who was shot at while she tried to escape the office, told the court: "I'll never forget the day the person I tried to help0 tried to end my life."

Leigh-Anne Hydes told Tully he was "an evil man" with an overrated sense of self-importance.

"He is an extremely clever man who has manipulated us and the justice system." She hoped he would never be able to walk "in any community again".

Hydes said she had been been badly affected by the gruesome scene at the Winz offices, while she sat on the floor tending to a wounded colleague. She spoke of overwhelming relief when police arrived and there was someone there to help.

She had not known for more than hour whether two other woman colleagues had lived. The women in the office were all friends – a tight knit work family. Hydes was later diagnosed with post-traumatic stress disorder.

CROWN SEEKS RECORD NON-PAROLE

The Crown asked for a 33-year minimum non-parole term as part of the life sentence for Ashburton WINZ shooter Russell John Tully.

Crown prosecutor Andrew McRae described the two 2014 killings as "cold blooded and calculated" as he argued for the long jail term for 49-year-old Tully at the sentencing before Justice Cameron Mander in the High Court at Christchurch.

He said Tully had entered the WINZ office "purposely and methodically", and he had gone there after making careful preparations, and with a "hit list".

There was cruelty in the shooting of one of the office workers who could be heard pleading for her life before Tully shot her twice more.

His shooting rampage which lasted 61 seconds, in which he fired six shots, was caught on security camera footage.

McRae said Tully had gone there to shoot as many people as he could.

Tully's amicus, James Rapley, asked for a 23 to 25 year starting point.

Experts found Tully had impaired mental health and personality disturbance. Tully's grandiose sense of entitlement contributed to his offending, Rapley said.

Tully was present for only a few days of his trial, because he twice disrupted proceedings by continuously shouting.

He was on a hunger strike during the first part of the trial, but returned to court when he began eating again.

TULLY CLAIMS 'COVER UP'

Tully told the High Court the Crown's evidence and other reports were a "major cover up".

He said he was not in his right mind at the time of the shootings. For many years he had a raised level of static on the head, he said.

Tully claimed he was denied access to doctors. The Crown was looking for someone to blame, he said.

LONGEST NON-PAROLE SENTENCES:

- William Bell: 33 years, which decreased to 30 years on appeal. He killed three people at the Mt Wellington-Panmure Returned Services Association in 2001.

- Bruce Thomas Howse: 28 years non-parole, decreased to 25 years on appeal. He murdered his stepdaughters, Saliel Aplin and Olympia Jetson, in 2001.

- Graeme Burton: 26 years. He murdered nightclub lighting technician Paul Anderson in Wellington in 1992. While on parole, he shot and killed quad biker Karl Kuchenbecker, 26 and attacked four others during a rampage in the Wainuiomata hills in 2007. He attempted the murder of Head Hunters gang member Dwayne Marsh in prison in 2008.