Constable Zachary Rolfe’s first shot was unlikely to have stopped Kumanjayi Walker wielding a pair of scissors, a combat surgeon has told his murder trial.

The Aboriginal teenager died after Rolfe, 30, shot him three times during a failed arrest in Yuendumu, 290km northwest of Alice Springs on November 9, 2019.

Prosecutors say Rolfe went “too far” when he fired the second and third shots, which are the subject of his murder charge, because Mr Walker was “effectively restrained” by another officer.

The constable says he was doing his job and defending himself from a violent offender who had stabbed him with scissors held in his right hand.

Expert witness Keith Towsey on Friday said Rolfe’s first shot into Mr Walker’s back was unlikely to have stopped the teen being able to use his right arm.

“It has not struck any major organs to cause a major haemorrhage,” he told the Northern Territory Supreme Court in Darwin.

“It has not affected the major muscle groups that provide power to the shoulder and it has not affected any of the nerve supply to the right shoulder.

“Anatomically, I cannot see how the missile track A1 would have affected his ability to use his right arm.”

Dr Towsey also said it was likely that Rolfe’s second shot into Mr Walker’s left torso killed him.

“It has gone from one side of the body to the other and in doing so it has passed through several major organs, in particular the liver, the kidney and spleen,” he said.

“These three organs in particular have a very rich blood supply and penetrating trauma to them causes quite extensive bleeding.”

Earlier, the jury heard that Senior Constable Anthony Hawkings, who witnessed Rolfe fire the second and third shots, had previously told investigators Mr Walker was contained when he was fatally shot.

Prosecutor Philip Strickland SC reminded him of his statement to police soon after the incident in which Sen Const Hawkings said: “It looked like (Rolfe and Constable Adam Eberl) had contained (Mr Walker) or were containing the guy”.

But on Friday he said Rolfe and Const Eberl “were in the process of attempting to contain Mr Walker” when the shots were fired.

“You said it looked like they had contained him or were containing him,” Mr Strickland said in reply.

“It was a very active situation,” Sen Const Hawkings responded.

“I saw them wrestling on the ground.”

Sen Const Hawkings also agreed with Rolfe’s lawyer David Edwardson QC that Mr Walker had not released the scissors he stabbed Rolfe in the shoulder with when he was shot.

“He was not incapacitated was he?” Mr Edwardson said.

“No,” Sen Const Hawkings replied.

Sen Const Hawkings’ body-worn camera recorded him running towards an open door at Mr Walker’s grandmother’s house after Rolfe fired his first shot.

As he approached the doorway Rolfe can be seen standing over Const Eberl and Mr Walker just before he fires the second and third shots.

Sen Const Hawkings told the court on Thursday that Mr Walker was laying on a mattress on the ground in a “semi-prone” position when Rolfe fired.

“I cannot recall if he was on his stomach or if he was more so on his side, struggling.”

Moments later the camera records Mr Walker laying face down with his arms and hands behind his back as Rolfe and Const Eberl handcuff him.

He was still holding the scissors in his right hand.

Prosecutors have conceded the first shot, which was fired while Mr Walker was standing and resisting arrest, was justified.

Rolfe’s second and third shots were fired from a distance of about 5cm.

The trial continues.

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