UPDATED 9.09pm Russell John Tully has been found guilty of murdering two Ashburton Work and Income workers.

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A jury took less than six hours to establish that 49-year-old Tully was the masked gunman who stormed the Ashburton WINZ office on September 1st, 2014 and shot dead receptionist Peggy Noble and case manager Susan Leigh Cleveland.

He was also found guilty of attempting to murder case manager Kim Adams.

However, Tully was found not guilty of attempting to murder case manager Lindy Curtis.

In addition he was found guilty on two charges of the unlawful possession of a firearm.

The jury found him not guilty of setting a man trap.

The CEO of the Ministry of Social Development said the guilty verdicts of Tully are a small step forward in the recovery of those involved.

Brendan Boyle said the shootings were an incredibly difficult thing for the organisation to experience.

"But, we've had a result today and we're grateful for that. There's a feeling of relief," he said.

In a statement Peggy Noble’s family, who have been present for much of the trial, acknowledged the support they had been given.

They also thanked each witness for the strength they displayed, which allowed the jury to reach the guilty verdicts.

Tully has been remanded in custody and will be sentenced on April the 15th.