Then on the morning of October 10, the offender grabbed a jogger from behind in Murrays Bay and violently threw her to the ground. She suffered a broken collarbone and concussion.
Two more serious attacks happened that same month, injuring both women involved.
Finally on November 8, the offender attacked a woman jogging on a track in Browns Bay.
He threw the woman to the ground punching her about the head 10 times. She also suffered a dislocated shoulder.
Crown prosecutor Sam Teppett read one victim impact statement to the Auckland District Court, elucidating the ongoing effects of violence described as "shameful" and "cowardly".
"You took away a piece of my freedom I will never get back," the woman had written.
She recalled trying to protect her face from the blows and seeing her blood flowing.
"I remember screaming … I have never been so scared in my life."
Returning home from the hospital she realised life would never be the same, the court heard.
She still could not go on walks alone because she felt unsafe.
The victims themselves were bravely in court, witnessing the offending be denounced by the justice system.
Also seated in the public gallery were several supporters of the young man.
Defence lawyer Julie-Anne Kincade, QC, said the continued family support he had was one of many features in the case that showed his prospects for rehabilitation.
She said her client was genuinely remorseful and had participated in restorative justice.
Judge Dawson said he needed to hold the young man accountable for the considerable harm he had caused. The unprovoked attacks were on five "complete strangers".
The judge said women in our community should be able to go out in public alone and feel safe.
But because of the offender's behaviour, and that of a small number of other men, this was not the case when it should be, he said.
Judge Dawson said an aggravating feature of the case was the extreme violence that had been used - two victims had been rendered unconscious in the attacks.
The offender had intentionally gone to "secluded places" where woman exercised alone and attacked them from behind.
The unsuspecting victims were vulnerable, the court heard.
"Your offending involved attacks to the heads of the victims," Judge Dawson said.
"That is inherently dangerous."
One victim in particular had been repeatedly punched about the head, he said.
It was not one-off impulsive behaviour, as it spanned across four months and he could have stopped at any time, he said.
Judge Dawson said the young man should be commended for attending restorative justice, as it could not have been easy.
His early guilty pleas to two charges of wounding with intent to cause grievous bodily harm, assault with intent to injure, wounding with intent to injure and injured with intent were also taken into account for a discount on his final sentence.
Kincade is seeking permanent name suppression for her client, which the judge will have to decide on later this year.
Waitematā East Area Investigations Manager, Detective Senior Sergeant Callum McNeill, said police wanted to acknowledge the sentencing for the "brazen and alarming" attacks.
Police recognised the attacks had caused "significant concern" in these communities at the time, he said.
"Police want to acknowledge the victims in this matter, for some of them the physical and psychological impacts of these assaults have had a long-lasting impact," McNeill said.
"I also want to acknowledge the team of detectives who worked on this investigation.
"It is through their dedication and hard work that police have been able to hold the offender to account and prevent any further victims."
