Ben McDevitt took the stand for the defence in the Darwin Supreme Court on Tuesday morning as the final witness in the murder trial of Constable Rolfe.

Mr McDevitt, who has almost 40 years experience in various law enforcement agencies, was responsible for formulating the "de-escalation model" of training that the NT Police has adopted, apart from some "slight variations", the court heard.

Constable Rolfe's lawyer, David Edwardson QC, put to Mr McDevitt a number of statements made last week by prosecution witness and NT Police officer of 25 years, Detective Senior Sergeant Andrew Barram.

One of them was that Constable Rolfe should have used "empty hand tactics" to assist his then partner, Remote Sergeant Adam Eberl, to subdue Mr Walker, who by that point had been wrestled to the floor by Sergeant Eberl.

This is instead of what Constable Rolfe did, which was shoot Mr Walker a second and third time in the torso from close range.

"It's a ludicrous statement and it's just not in accordance with the training or the use of force model," Mr McDevitt said about Senior Sergeant Barram's evidence.

Mr McDevitt also said, contrary to previous expert witness testimony, that Sergeant Eberl was actually in more danger once he and Mr Walker were on the floor.

"The evidence would appear to me to show that throughout that struggle Mr Walker remained armed with the edged weapon and it would appear, certainly from his statement after the third shot that he intended on using it," he said.

The court has previously heard that the threat to the officers had largely been removed by Mr Walker being pinned to the floor.

During cross-examination, Crown prosecutor Philip Strickland SC pointed out a number of failures Mr McDevitt had noted in his report about Constable Rolfe and Sergeant Eberl's actions on the night.

These included that they got too close to Mr Walker, that they entered the house Mr Walker was in without a clear plan of action and that they failed to alert other police officers that they were in a house with an "unknown male".

"Can you explain then why you say that he was acting in accordance with his training when he entered [the house] without a clear plan of action?" Mr Strickland asked.

"I've pointed out six areas where I believe, in hindsight, that there were tactical errors that I believe that the police officers made," Mr McDevitt said.

Mr McDevitt said the officers made the errors because they weren't aware at the time that the man they confronted was in fact Mr Walker and that he was armed.

Mr Strickland also questioned Mr McDevitt about why he said it was appropriate for Constable Rolfe and another officer, Constable James Kirstenfeldt, to enter another house in Yuendumu where two children were present around 10 minutes before the shooting.

"Do you think that before a police officer enters a house, or entered that house, with their hand on the Glock, being ready to deploy it, that any children should have been evacuated beforehand?" he asked.

Mr McDevitt replied, "No ... it wouldn't have been practical.

Mr Strickland asked, "How do you know that sir?

Mr McDevitt replied, "I've gone into dozens of houses, with far more fire power than what Mr Rolfe had, which have had children inside them."

Constable Rolfe has pleaded not guilty to murder, as well as two alternative lesser charges, for shooting Mr Walker three times during an attempted arrest in the Central Australian community of Yuendumu in November 2019.

The charges apply to the second and third shots, with the first being seen as legally justified.

The trial continues.