Benjamin Glenn Hoffmann pleaded guilty mid-trial in November to intentionally killing Hassan Baydoun, 33, Michael Sisois, 57 and Rob Courtney, 52, and the manslaughter of 75-year-old Nigel Hellings, on June 4, 2019.
The 48-year-old's sentence has since been delayed numerous times for a variety of reasons, including the loss of his Legal Aid funding after he sacked two legal teams.
During his latest appearance in the Northern Territory Supreme Court on Monday, Justice John Burns was obliged to allow him to question witnesses and give evidence because he does not have a lawyer.
Hoffmann opened proceedings by telling the court his trial lawyers had ignored crucial medical evidence about his mental state and treatment since the killings.
But lawyer Patricia Petersen, who is assisting but not officially representing Hoffmann, contradicted him, saying his previous legal team had done a good job and she had his medical records up until 2021.
Hoffmann also accused witness David Greenberg of not assessing all the evidence when he wrote a series of expert psychiatric reports for the prosecution that found the gunman was not psychotic or suffering from a mental illness when he pulled the trigger.
During a protracted 40-minute examination of Professor Greenberg, Hoffmann made a series of mostly incoherent statements, including that he has been prescribed 410mg of anti-psychotic drugs a day and this was proof he was suffering from schizophrenia.
The court also heard Hoffmann had suffered a breakdown in prison while awaiting his sentence and "covered himself in his own s*** because he felt like s***".
The proceedings became farcical when Justice Burns asked Hoffmann if he wanted to give evidence to the court, to which he replied: "Do you want me to give evidence?"
Justice Burns repeated the question numerous times but the gunman failed to answer it before stating he would think about it during the lunch break.
Hoffmann intimated that he would give evidence about being handed the shotgun he used to kill his victims 20 minutes before he started his rampage, to which Justice Burns replied that it was already an agreed fact.
The convicted murderer also repeatedly stated that Justice Burns needed to view his complete medical records, including those from 2022, but Justice Burns said he would not adjourn the proceedings.
Hoffmann was high on methamphetamine when he shot the four men dead while hunting a man named Alex Deligiannis, who he believed had stolen his ex-girlfriend, Kelly Collins.
He shot Mr Baydoun four times with a double-barrel shotgun at the Palms Motel in central Darwin.
Mr Hellings was gunned down through the front door of his apartment block about 800m away.
Hoffmann's next victim was his mate, Mr Sisois, who he shot in the head in the car park at the nearby Buff Club bar and restaurant.
Mr Courtney was murdered at an industrial yard at Darwin Recycling, about 2.5km away.
He was found with 69 injuries, including 36 stabbing and slicing wounds, multiple blunt force injuries and a gunshot wound.
Mr Deligiannis had previously visited three of the locations regularly.
Hoffmann and Ms Collins met in early 2019 in a drug rehab centre, where the pair made plans to move in together after they left the program
But two weeks before the shootings, Ms Collins sent Hoffmann a text message saying she was in love with Mr Deligiannis.
The hearing continues.
