A middle-aged Greek Australian man is one of the victims of the Darwin massacre that took place at the Palms Motel about 5.40pm on Tuesday and cost the life of four people.

According to Neos Kosmos sources, Michael Sisois was shot dead during the shooting rampage.

The 45-year-old suspect, Ben Hoffman, who witnesses said was armed with a pump-action shotgun, travelled in a ute, which he had previously “borrowed” from the company he used to work for and belongs to a Greek Australian.

According to sources the 45-year-old plumber was fired from his work due to his poor attendance record,

NT Commissioner for Corrections Scott McNairn confirmed the man had been released on parole in January after being sentenced to six years jail, with a non-parole period of four years and was wearing an electronic monitoring bracelet.

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He had previously breached parole for breaking curfew, for which he was given a 14-day custodial sentence, the commissioner said.

He had also undergone random drug tests, which he passed.

Specialist police from the tactical response group tasered the alleged shooter and wrestled him to the ground, kicking away his shotgun and arresting him at the corner of McMinn and Daly streets next to a car he was driving.

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The Northern Territory government has ordered a review of the 103 people currently on parole following the shooting.

Police said the alleged offender is at Royal Darwin Hospital under police guard and is expected to be charged soon.