Darwin resident Ben Hoffmann has been identified as the man suspected of killing four men after he opened fire in the Darwin CBD last night.
Multiple crime scenes including the Buff Club, Palms Motel, a Coles Express and the Peter McAulay Centre are areas of investigation.
So far at least one other victim, a woman, were injured and taken to hospital for treatment.
It has been reported that the suspect was armed with a pump-action shotgun.
The 45-year-old was arrested an hour after the spree at about 6.45pm after trying to enter police headquarters in what Police Commissioner Reece Kershaw said may have been an attempt to hand himself in.
The man was known to police – Hoffmann was on parole and was wearing an electronic monitoring bracelet.
NT Chief Minister Michael Gunner told a media conference the incident was not believed to be terror-related.