Sentencing began with the 24-year-old woman Mitchell attacked at the quarry reading a Victim Impact Statement.
READ MORE:
The Big Read: Riverhead quarry attacker Colin Mitchell's revolting previous rapes
The Big Read: Riverhead quarry attack - from glittery cocktails to terror in the dark
Riverhead quarry attacker Colin Mitchell's dark past revealed
The contents of her statement were suppressed by Justice Fitzgerald, meaning the Herald cannot report what the survivor told the court.
The woman was emotional but was able to tell the court about the significant impact Mitchell's brutal offending had on her.
As she read, Mitchell sat in the dock, his face expressionless.
The quarry attack survivor supported in court by family members and a woman Mitchell raped in 1984 - whose case was referred to during the trial as propensity evidence by the Crown.
Other friends and family, and the team of police who led the investigation into Mitchell's offending, were also in court.
Crown Prosecutor Kirsten Lummis said the victim was still "fighting back" to return to her normal daily life after the "sheer terror" Mitchell inflicted on her.
"And incident that is only a moment in time - less than an hour - for the victim has repercussions that can last and will last a lifetime," she said.
The 1992 survivor was not in court and did not provide a Victim Impact Statement but Lummis said the woman's evidence during the trial clearly showed the ongoing effects of her ordeal.
Lummis said there were significant aggravating factors to both the 1992 and 2017 attacks.
She said there was planning, premeditation and the only appropriate sentenced was preventive detention.
"In light of the lengthy period of offending," Lummis said.
"Yes, there are gaps but the Crown submits that does not detract from the nature of the offending."
Defence lawyer Mark Ryan said a "lengthy determinate sentence was preferable".
He said the gap between offending, 25 years between Riverhead and the 1992 attack and a seven year period between that and his 1984 rape, showed there was "no pattern" to Mitchell's actions.
He suggested a determinate sentence followed by an extended supervision order would be more appropriate.
The Parole Board would be responsible for making such an order but Ryan suggested Justice Fitzgerald could "endorse" it in advance.
The sentence
After hearing from the Crown and defence, Justice Sally Fitzgerald outlined the facts of his offending.
She said the Victim Impact Statement showed the "devastating effect" of Mitchell's crimes.
"Your offending and its aftermath… have been an understandingly harrowing ordeal," she said.
Justice Fitzgerald acknowledged the dignity of both victims throughout the court process.
She said the sentence had to reflect the seriousness of offending, denounce his actions and protect the community from him in future.
She said called Mitchell's offending was "disturbing".
In both 1992 and 2017 he and he knowingly took advantage of vulnerable women with a high degree of planning and premeditation.
Serious violence was evident in both cases.
Expert reports submitted to the court revealed Mitchell was at a high risk of reoffending - particularly sex offending against vulnerable adult females who are strangers to him.
He continued to deny his offending and minimised previous offending - but only incidents he was prepared to acknowledge.
Justice Fitzgerald said Mitchell had health issues including bladder cancer and diabetes and claimed he had been subjected to violence at the hands of his father when he was a child.
But she could give him no discount in sentencing for those factors as he had shown a "clear and disturbing pattern of sexual offending".
"Over decades… your sexual deviancy has not diminished over time and escalated ins seriousness," she told Mitchell.
She said Mitchell's predatory nature offending against strangers, his seeking out of vulnerable victims, violence, threats of further violence and removal of victims to remote locations to avoid detections meant the community needed to be protected for him.
She had "no doubt" Mitchell would reoffend in future.
"There is no basis for me to conclude that it will stop," she said.
She sentenced Mitchell to preventive detention and ordered him to serve at least 10 years before he becomes eligible for parole.
What Colin Jack Mitchell did
On March 2, following a 12-day trial, Mitchell was found guilty of six charges relating to two sexually motivated attacks 25 years apart.
In 2017 Mitchell kidnapped a young woman walking home from the annual pride parade in Ponsonby.
He drove her to a quarry in Riverhead and assaulted her, with an intent to sexually violate her, and threatened to kill her.
He was also found guilty of raping a woman in May 1992 - a crime that he was tried for after DNA evidence found in the quarry attack linked him to a historic sex crime.
Mitchell has served time for sexual offending previously.
He was sent to prison for five years after raping a 19-year-old in 1984.
Details of the assault were revealed to the jury during the trial after the Crown successfully applied to use propensity evidence as part of their case.