Police were called to Mitchell St, Aramoho, about 7pm when Suos' ex-partner reported that he had punched her.
Suos, 32, was standing in the doorway of a sleep-out on the property when officers arrived and when they told him he was under arrest he pulled out a firearm he had concealed inside his jacket and pointed it at the officers.
The officers returned to their car and the Whanganui Armed Offenders Squad (AOS) arrived to put up a cordon about 8pm.
Shortly after Suos stepped out of a sleep-out. He did not respond to commands that he put his hands in the air and walked towards one of the AOS officers and raised a sawn-off shotgun towards him.
The AOS officer fired three times at Suos from his Bushmaster rifle. One bullet his upper arm and another entered his abdomen, causing irreversible blood loss.
The officer told the authority that Suos had "transitioned into a firing position" and that "there's no way he could've missed me if he fired with a sawn-off because the spread would be... huge".
Suos was of Cambodian descent, had lived in New Zealand for about 20 years and was living in Upper Hutt at the time.
He had been convicted of a range of offences including family violence.
In 2009, Suos was jailed for five years after tying up a taxi driver with a metal dog chain and stealing his bank card.
He and an accomplice were convicted of a number of charges including kidnapping and aggravated robbery. Suos was also convicted of stealing the victim's taxi.