Her son died in her arms after she rushed to the scene.
"When I got there my son was lying on the ground, I couldn't see any blood, I couldn't see any bullet hole," she said.
Her boy uttered: "I have been shot, Mum. I love you."
Sellars didn't believe McKee showed any remorse during the trial and she now self-medicates to cope with her son's death.
"Why won't you admit what you did?" She asked McKee.
"It takes a brave man to stand up to what they've done. The only brave man I see is my son."
She said the only grace in her boy's death was that he "is now with his brother".
Armed police at the scene of the shooting on Winsford St in Auckland last year. Photo / Brett Phibbs
McKee also produced a letter that he wished to be read before the court.
"I understand that this is a serious offence, and my actions have changed many lives forever, not just my own, but my victim's family and the community at large," he said.
"I am truly sorry for what I have done and the losses that all have to go through."
As Ives argued for a reduced sentence for her client, Justice Muir interrupted and said she was placing "a very low tariff on human life".
However, during his sentencing remarks, he said McKee's actions could be described as "excessive self-defence" and did not intend to fire a fatal shot, but rather a warning.
The judge said McKee was at a "complete crossroads in his life" as to whether he welcomed his rehabilitation or continued down a criminal path.
McKee and Putt had been on the run from police at the time of the shooting. The gun, described as a dark-coloured pistol wrapped in tape, has never been found.
McKee has several prior convictions, including possession of an offensive weapon in 2011, and injuring with intent to injure in 2012.
Justice Muir said he suspects "there is a back story to all of this that none of us know".