After hearing a loud bang outside Darwin's Buff Club, plumber Malcolm Smith and his mate put down their beers and went to investigate.
"I said to Michael what the f*** was that," as he recounted the events on the afternoon of June 4, 2019, when Benjamin Glenn Hoffmann allegedly murdered four people during a drug-fuelled rampage across the city.
"I was a bit suspicious because the noise was so loud ... like a car backfiring," he told the Northern Territory Supreme Court on Tuesday.
The duo walked out of the members-only bar and restaurant and Mr Smith's attention was drawn to the centre of the car park.
"I noticed a pair of feet poking out behind the concrete bollard," he said.
"I approached the man and he had his arms up and he was twitching ... and his head was missing from just above his eyebrows."
The dead man was Michael Sisois, 57.
He was Hoffmann's third victim in less than an hour, prosecutor Lloyd Babb SC says.
Hassan Baydoun, 33, was shot three times in the Palms Motel and Nigel Hellings, 75, died after he was shot in the groin inside his home at a nearby apartment complex.
Rob Courtney, 52, died after he was stabbed more than 30 times and shot.
"I noticed an empty cartridge from a shotgun ... I said to Michael 'call the cops', I think it was a gunshot," Mr Smith said.
Laurence Gibson was also having an after-work drink at the Buff Club when Mr Sisois was shot.
He told the court he spotted Hoffmann, who he had known for several years, driving from the club in a white ute after the incident.
Constable Kevin Rankine was one of the first police officers to respond to triple-zero calls reporting shots had been fired at the Palms Motel about 5.45pm.
"I didn't even know where it was. I had to Google it," he said.
"I assumed people were just letting off fireworks. That was our attitude as we left."
When Constable Rankine arrived at the motel, he was told a woman had been shot in the leg and the gunman was moving towards a nearby apartment complex.
He and his partner also heard gunshots as they arrived on Garden Hills Crescent near the apartments before a higher-ranked police officer told them to pull back.
"I think he thought we were about to drive into firing or something," he said.
The pair then heard two or three more shots.
"We ignored the sergeant's direction because we heard the additional shots and thought 'f*** let's go'," he said.
The pair walked into the unit block to investigate several minutes later.
Const Rankin said he had a clear view of the Buff Club from the rear of the property, several hundred metres away.
"I thought I saw a white dual cab ute approaching Buff Club," he said.
"I couldn't be certain but in hindsight, I realise it was him."
The pair then heard a single gunshot ring out but they weren't able to determine which direction it had come from.
Minutes later, another police unit reported a shot has been fired at the club.
"As we approached Geranium Street I told (my partner) to keep driving because the vehicle could take more of the shot than we could," Const Rankin said.
"I wanted to use it as cover. As we crept around the corner ... I was thinking what the f***".
Const Rankin said he wanted to get into the club as quickly as he could to "hopefully catch him unaware before he hurt someone else".
Hoffmann has pleaded not guilty to four counts of murder and 10 other serious charges, including threatening to kill and recklessly endangering life.
The trial continues.
