Mr Coates told the Launceston Supreme Court that Jack Harrison Vincent Sadler, 29, planned to execute and disposed of Mr Anderson-Brettner in a brutal way which showed how angry he was with him.

Mr Sadler has pleaded not guilty to the alleged murder on August 15, 2018, at his house at Dion Crescent, Riverside.

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He urged the 10-man and two-woman jury to consider the whole of the evidence in the circumstantial case.

Defence counsel Greg Richardson will sum up the defence case this afternoon.

Mr Coates said that if Mr Sadler's evidence on Monday was true about a confrontation between the Victorian drug dealers and Mr Anderson-Brettner before he was killed "they must have been the quietest drug dealers ever".

He said it was unchallenged evidence from Mr Sadler's partner at the time, Gemma Elizabeth Clark, that she heard only two voices.

Mr Coates cited three times during Clark's evidence that she said there was nobody else there.

"Did you only hear two people," he quoted from the transcript.

"Yes," Clark said in evidence.

Mr Coates said that forensic evidence did not support Mr Sadler's version.

"You might think that even a Victorian drug dealer might be nervous and sweaty and might shed DNA everywhere but there is no evidence of that," he said.

He said that Mr Sadler's DNA was found on the magazine, silencer, handgrip trigger guard, outer surface and muzzle of the Smith and Wesson 9mm self-loading pistol.

He said forensic scientist Carl Grosser gave details of the percentage of DNA on the areas of the weapon was up to 98 per cent compared with a second contributor.

Mr Coates said that Mr Sadler's demeanour in the witness box did not reflect what jury members might have thought was an extremely distressing event.

"He didn't seem too distressed when giving evidence yesterday, he seemed more concerned with telling what a good drug manufacturer he was," Mr Coates said.

He said that Mr Sadler's evidence that he was terrified after the drug dealers killed Mr Anderson-Brettner did not accord with the shopping trip expedition and gym visit the day after.

Mr Coates said Mr Sadler's evidence that he and Mr Anderson-Brettner were standing with their back to a wall when Mr Anderson-Brettner was shot did not accord with the evidence of former State Forensic Pathologist Dr Christopher Lawrence.

"Dr Lawrence said Mr [Anderson] Brettner was shot in the back-its just impossible that it happened that way," he said.

Mr Coates said Mr Sadler's actions after the shooting were consistent with a number of aspects of the song Dead Body Disposal that Clark said Mr Sadler was listening to "all the time".

"The major things he did are consistent with the song, cutting the body into six pieces, double-bagging body parts, putting chilli powder and baby oil in the garbage bags and disposing of the bags in wheelie bins," he said.

He said the actions were consistent with Mr Sadler being angry with Mr Anderson-Brettner, meeting with former lawyer Adrian Hall to discuss disposing of a body and missing persons details, buying plastic gloves and materials, the song and Clark hearing just two voices at the house.