The former lover of a man on trial accused of murdering four people during a rampage across Darwin is among the witnesses expected to give evidence this week.

Benjamin Glenn Hoffmann, 47, has pleaded not guilty to four counts of murder during a drug-fuelled shooting spree on June 4, 2019.

The Crown says he was searching for a woman he believed was his girlfriend, Kelly Collins, when he gunned the men down at four different locations.

According to Hoffmann, Ms Collins was an “ex-working girl” struggling to beat drug addiction.

He said the pair had a relationship and he was trying to help her beat her methamphetamine dependency.

But she was preyed upon by drug-dealing men who lured her into sex work and abused her.

Prosecutor Lloyd Babb SC has said Hoffmann was also trying to find a man named Alex Deligiannis when he stormed the Palms Motel and a nearby apartment block armed with a shotgun.

Hoffmann has described Mr Deligiannis in unflattering terms and accused him of interfering in his and Ms Collins’ relationship.

Witness Steven Barlee says Hoffmann regularly stated he was going to kill a man named Alex in the weeks before the shooting.

“He said he was going to get Alex, shoot him, blow his head off, bash him with a baseball bat. Many times,” Mr Barlee told the Northern Territory Supreme Court.

Mr Deligiannis is also expected to give evidence in the coming days.

Another witness, Agapitos Agapitos, told the court he warned Hoffmann off Ms Collins “because she was a junkie”.

“He told me that Kelly was getting used. He told me sometimes they raped her … Alex was pimping her,” he said.

Mr Agapitos said Hoffmann became upset when he discussed the matter.

“He said he wanted to get a baseball bat and go and smash (Alex’s) head in,” Mr Agapitos said.

“I didn’t want him near her because she was always angry and she wanted to beat him up.

“I told him ‘you’ll end up in jail’ … It’s Alex’s girlfriend anyway.”

The Crown says Hoffmann shot dead Hassan Baydoun, 33, at the Palms Motel and Nigel Hellings, 75, at an apartment complex.

Michael Sisois, 57, died from a gunshot to the head in the car park at The Buff Club and Rob Courtney, 52, was stabbed more than 30 times and shot dead at Darwin Recycling.

Mr Sisois and Hoffmann have been described by witnesses as “best friends”.

But Hoffmann has said he believed Mr Sisois tried to poison him two days before the shootings.

He also sent Mr Sisois a text a day before he allegedly murdered him demanding that he bring a woman to him, Mr Babb has said.

“I will f***ing wreck you, Sisois. Bring her to me. I’ll f*** you up,” the message read.

Hoffmann has also pleaded not guilty to 10 other serious charges, including threatening to kill and recklessly endangering life.

The trial continues on Monday.