A jury has found police officer Zachary Rolfe not guilty of murder over the fatal shooting of Aboriginal teenager Kumanjayi Walker, after a month-long trial in the Northern Territory Supreme Court.

WARNING: Aboriginal and Torres Strait Islander readers are warned the following article contains images of deceased persons.

After deliberating for just under seven hours, the 12 men and women returned their verdict this afternoon.

When the decision was handed down, the 30-year-old was calm, hugged his mother and smiled.

Outside the court, Mr Rolfe said it was "the right decision".

"But a lot of people are hurting today, Kumanjayi's family and community… so I'm going to leave this space for them," he said.

The NT constable was charged with murder and also faced alternative charges of manslaughter and engaging in a violent act causing death.

On November 9, 2019, Mr Rolfe and four fellow police officers were dispatched from Alice Springs to arrest Mr Walker.

At dusk, Mr Rolfe and his partner Adam Eberl found Mr Walker inside a dark house.

When the 19-year-old produced a pair of scissors from his pocket, a struggle took place.

Mr Rolfe was stabbed in his left shoulder, before he fired his Glock three times.

The Crown accepted the first shot was legally justified, because there was a reasonable possibility Mr Rolfe believed it was necessary to defend himself.

However, when he fired a second shot 2.6 seconds after the first, and a third shot 0.5 seconds later, they argued the situation had changed because Mr Rolfe's partner had restrained Mr Walker on the ground.

In his closing address, prosecutor Philip Strickland SC told the jury they should have "little difficulty" in finding Mr Rolfe intended to kill Mr Walker, or cause him serious harm, at the time of the last two shots.

He added that based on the evidence, the jury could conclude that the accused did not see Mr Walker stabbing Constable Eberl and he did not fear for his life when he fired shots two and three.

"The Crown case is that the evidence that the accused gave in court, that he did have those beliefs, was a lie, and the accused lied to justify the unjustifiable; namely, the fatal shooting of Kumanjayi Walker," Mr Strickland said.

In his closing address, Mr Rolfe's counsel David Edwardson QC said his client had no time to form any intent and that he instinctively responded to the threat of the scissors which Mr Walker deployed against both officers.

"If Kumanjayi Walker had stabbed either officer in the neck, to that depth, death would almost certainly have been inevitable," he said.

"In this case, between shot one and shots two and three, Kumanjayi Walker always remained in control of the scissors in his right hand.

"The evidence does not prove otherwise.

"He was, at all times, non-compliant with violent resistance, even after three bullets had entered his centre body mass, the exact location where Zachary Rolfe had been trained to aim.

"Each time (Mr Rolfe) pulled the trigger, he was acting in good faith.

"He was acting in the reasonable performance of his duties, and he was acting in self-defence; the self-defence of himself and his partner.

"In these circumstances there can be only one verdict and that is one of not guilty to all charges."

Mr Edwardson also addressed Mr Walker's criminal record.

"Three days before 9 November 2019, he had deployed an axe (against two officers) in an extraordinarily dangerous and confronting manner, which of itself, would have justified him being shot on that occasion," he said.

"(Mr Walker) might be a young man, and for that reason, if nothing else, this case is tragic.

"But, nonetheless, he was dangerous. He was violent.

"And in many respects, he was the author of his own misfortune."

The defence counsel added Mr Rolfe was arrested within four days of the shooting "without any proper investigation".

"The executive of the Northern Territory Police Force and those they deployed to justify these charges, you might think, have thrown everything at Zachary Rolfe because of a decision that should never have been made," Mr Edwardson said.

Murder in the Northern Territory carries a mandatory life sentence and anyone convicted of the offence is not eligible for parole for 20 years.

NT Police Association President Paul McCue spoke after the verdict, describing the past few years as "very traumatic for a lot of people".

"It was a tragic day, a young man lost his life, but let's not forget Constable Rolfe," Mr McCue said.

He said Mr Rolfe and his partner were "set upon viciously" and described the murder charge as "a travesty".

Mr Walker's family and senior Yuendumu elders have responded to the not guilty verdict handed to Mr Rolfe.

They said the verdict is a result of racism and have asked for guns to be banned in remote Aboriginal communities.

"We don't want guns in remote communities, enough is enough," Yuendumu elder Ned Hargraves said in an emotional address outside court.

Mr Walker has been named and identified with the permission of his family.