A lovesick man accused of murdering four people during a drug-fuelled rampage across Darwin before claiming he was temporarily insane wasn't psychotic, a court has been told.
Benjamin Glenn Hoffmann has pleaded not guilty to four counts of murder on June 4, 2019, saying he'd been poisoned and it had caused him to be "out of his mind".
Psychiatrist Robert Parker examined the 47-year-old in police custody about three hours after the four men were shot dead in less than an hour at four locations
"At that time, Ben was not suffering a significant disturbance of mood or psychosis or active cognitive impairment," he told the Northern Territory Supreme Court on Wednesday.
Prof Parker also said he found no signs that Hoffmann had been poisoned as he had claimed or involuntary intoxication.
"There was no evidence ... in his mental state at that time that he appeared to be slurring his speech or having problems with his coordination," he said.
During the examination, Prof Parker also asked Hoffmann if he'd experienced any hallucinations or if voices were telling him to perform actions, to which he replied 'no'.
Forensic physician Angela Sungalia agreed, saying Hoffmann's movements in the hours before the shooting spree were calm and calculated.
"Such as acquiring the gun, arranging to meet Mr Sisois (the third man to die), approaching a property and providing the excuse that he saw a dingo," she said.
"The episodes are purposeful, show thought-out behaviour, and his rational conversation with Senior Constable Aiken and using the dingo excuse to allay suspicion is not in keeping with a psychosis."
The court has heard Hoffmann, who suffers an anti-social personality disorder, was high on methamphetamine during the rampage.
Dr Sungalia said the drug was unlikely to have caused him to suffer a psychotic episode but it could have caused him to become paranoid, aggressive and violent.
"He became disinhibited and he was angry to the point that he acquired weapons and he searched for specific people who he believed had injured him by poisoning and who he believed had led his girlfriend astray," she said.
After the killings, Hoffmann told police he believed he'd been poisoned the night before and it had caused him to be "out of his mind" and temporarily insane.
He also told Prof Parker he'd suffered a brain injury and loss of memory from a prison cell bashing in early 2019.
But police video of Hoffmann during a traffic stop several hours before the first shooting shows him to be polite and respectful towards Senior Constable Scott Aiken.
Later the same day, he went to a property on Darwin's outskirts near to where his former girlfriend, Kelly Collins, lived and told a resident he had seen a dingo in the area as he searched for her.
Forensic toxicologist Dimitri Gerostamoulos told the court Hoffmann had 0.9 milligrams per litre of methamphetamine and 0.2 milligrams per litre of amphetamine in his blood soon after he was arrested on June 4.
"That's a significant amount of that drug in blood ... consistent with someone using or consuming a significant amount of methamphetamine," he said.
Prosecutor Lloyd Babb SC says Hoffmann's first victim, Hassan Baydoun, was fatally shot four times at the Palms Motel in central Darwin.
Hoffman then allegedly shot Nigel Hellings through the front door at the 75-year-old's apartment block about 800m away.
The third man to die was Hoffmann's good mate, Michael Sisois.
The 57-year-old's body was found with a single gunshot wound in the car park at The Buff Club bar and restaurant.
Hoffmann is also accused of murdering Rob Courtney, 52, at an industrial yard at Darwin Recycling about 2.5km away
The trial continues on Thursday.
Australian Associated Press