A gunman convicted of murdering three people in Darwin and killing another during a drug-fuelled shooting spree may be too mentally ill to be sentenced.
Benjamin Glenn Hoffmann pleaded guilty in November to murdering Hassan Baydoun, 33, Michael Sisois, 57, and Rob Courtney, 52 and the manslaughter of Nigel Hellings, 75, on June 4, 2019.
The 47-year-old then sacked his lawyers before he was sentenced, saying they had been arguing and he had lost faith in their ability to defend him, and he was in need of expert advice.
Hoffmann has since found a new lawyer, Bruce Levet, who says his client is unfit to plead and properly instruct a lawyer ahead of his sentencing.
"As a result of material that was before the court from psychiatrists and the history ... there were certain red flags which raise fairly and squarely the matter of Mr Hoffmann's mental state," he told the Northern Territory Supreme Court on Friday.
Mr Levet said Hoffmann appeared delusional and believed there was a "conspiracy related to an outlaw motorbike group here in Darwin which was aimed against him".
"Hoffmann indicates to me ... that his previous legal team was part of the conspiracy and that those who sit to my left at the bar table are part of the conspiracy and that Your Honour is part of the conspiracy."
Mr Levet said he took ethical advice from senior members of the legal fraternity and met with Hoffmann to assess him about his capacity to give instructions to a lawyer.
"It was a difficult two and quarter hours. Mr Hoffmann from his point of view, he was cooperative. He was polite. He tried to be responsive," he said.
"However, leaving aside the delusional aspects ... it was very hard to get Mr Hoffmann to address questions and propositions."
Mr Levet said he feared Hoffmann may never be able to give instructions about his sentencing.
"We are at something of an impasse," he said.
Justice John Burns said it raised a difficult question about what the court should do if there was evidence an offender, after entering a guilty plea, had become unfit to continue with the sentencing.
"If counsel aren't able to take instructions from the offence for the purposes of the sentencing hearing it makes it extremely difficult for them to appear on his behalf," he said.
Justice Burns adjourned the matter to April 1 so he could research his powers to order an investigation into Hoffmann's fitness to plea.