Dyhrberg and Saurine have been charged as all three defendants allegedly had a common intention to rob or extort the occupants of Mr Zanco's rural home at Amamoor, about 130km north of Brisbane.

Crown prosecutor Michael Lehane said Caulfield had a firearm and the other two knew he was going to use it as they crammed into a two-man utility and drove to the property.

"We're not dealing with an "Ocean's 11" scenario ... there's no George Clooney, no planning over months; it was primitive in the extreme," Mr Lehane said during his closing statement on Monday.

Mr Zanco was waiting for housemate Andrew Donney to return home when the defendants arrived.

"They came in numbers expecting Donney to be there but Michael Zanco would do and he was shot dead because of drugs and because Caulfield could not control his rage," Mr Lehane said.

The prosecutor said Caulfield with his rifle, Saurine with a machete and Dyhrberg confronted the 22-year-old Mr Zanco, who weighed just 59 kilos and had done absolutely nothing to harm them.

"The plan had the potential for death from the start," Mr Lehane said.

The jury was told by Mr Lehane that their options included finding Caulfield guilty of intentional murder or the alternative charge of manslaughter.

The jury could also find Saurine and Dyhrberg guilty of murder by way of death caused during unlawful activity.

"It is the position of the Crown that all three are guilty of murder," Mr Lehane said.

Mr Lehane was due on Tuesday to continue his closing with each of Caulfield, Saurine and Dyhrberg's barristers to give their statements this week.