The man accused of the worst mass shooting in the Northern Territory's history will face a Darwin court on Friday morning charged with murder.
NT Police on Thursday charged 45-year-old Ben Hoffmann with four counts of murder, two of recklessly endangering serious harm and one of criminal damage with more charges expected over Tuesday night's deadly shootings in Darwin.
Hoffmann will appear in court via video link from prison.
He is believed to have known two of the four men he is accused of shooting and killing in the bloody rampage.
One of the men he knew, 52-year-old Darwin casino security guard Rob Courtney, appears to have fought for his life and stabbed Hoffmann after he charged in.
Hoffman has had surgery for knife wounds since being Tasered and arrested by police on Tuesday night, which delayed detectives interviewing and charging him until Thursday.
Northern Territory Police charged 45-year-old Hoffmann with four counts of murder.
The four killings occurred in about 30 minutes, with the gunman appearing to target specific locations.
Police believe he was affected by the drug ice during the mayhem, which he has a history of using.
Police have not ruled out an accomplice being involved because the ammunition used with the pump action 12 gauge shotgun was purchased by a "well known associate" of Hoffmann's, police commissioner Reece Kershaw said.
When asked about the gunman's motives, he said there was potentially disputes relating to drug debts and a woman.
"There is a bit of both there. There is drugs, I think, I am speculating here, but we are following those two lines," Mr Kershaw said.
The violence started at 5.39pm Tuesday at the Palms Motel where Hoffmann allegedly shot and killed taxi driver Hassan Baydoun, 33, who was on a meal break.
Mr Baydoun's cousin Abdallah Salman said his relative did not know the shooter and was accidentally caught up in the shootings as the alleged gunman went from room to room firing his gun and shouting for a person named Alex.
A 23-year-old woman at the Palms who police do not believe knew Hoffmann was shot in the legs and remains in hospital.
The shooter went on to kill Nigel Hellings, 75, in Gardens Hill Crescent less than a kilometre away, at what might have been the former home of an associate.
He then killed Michael Sisois, 57, who knew Hoffmann, after previously working together, a few hundred metres away in the car park of the Buff Club.
He then drove two kilometres to Woolner where he tried to enter police headquarters, kicking the door before phoning duty superintendent Lee Morgan who negotiated with him and alerted police to his location.
Mr Courtney was facing a charge of attempted sexual intercourse without consent and was due in court on Thursday.
The person named Alex, who Hoffmann was looking for in the days leading up to the killings was interstate and was charged a fortnight ago in Darwin with various traffic and drug offences.
Vincent Sisois, the brother of Mr Sisois, angrily asked why Hoffmann had been released from prison on parole recently given he was known to be dangerous and violent.
"Why was he let out, they knew something would happen and they let him out. Why?" Mr Sisois said.
The NT government has asked for a report from the Parole Board on Hoffmann and to review all people on parole, however, Attorney-General Natasha Fyles defended the system on Thursday.
Hoffmann is from a respected local family involved in business.
