Corrections did all it could to monitor the man who went on to rape and kill Blessie Gotingco, the department's northern regional commissioner says.
Tony Douglas Robertson was wearing a GPS monitor, but victim support advocates say he should have also been physically monitored or under armed guard when he was released in 2013 after serving eight years for crimes including abducting and sexually abusing a child.
Before his release, Corrections had sought the maximum 10-year Extended Supervision Order placed on the country's most dangerous criminals.
Justice Wylie granted the order, saying Robertson was very high risk, highly likely to reoffend and the harm to his victims would be very serious.
When he murdered Blessie Gotingco last May, Robertson was under release conditions that were similar to the extended supervision order that was to kick in in June; a GPS bracelet, curfew and a ban on drug and alcohol use.
Gotingco family spokesperson Ruth Money said it had failed.
"There were so many points in this offender's history to indicate to the system or the Corrections department that he was out of control," Ms Money said.
"He's a so-called monitored offender and no one was monitoring him. It's as simple as that, it was a preventable death," she said.
Just weeks out of prison, Robertson breached the terms of his release at least twice.
He was jailed for a month, then allowed back into the community.
Ms Money said Corrections should have ratcheted up the surveillance then.
"He should have been managed physically. So, the GPS bracelet, in conjunction with regular, random searches of his apartment, regular dropping in to see what he's up to, regular surveillance of his activities," she said.
"Within a month [of his release], he's in a public park. That says to me, and it should have said to Corrections, that he was going to reoffend."
Corrections' northern regional commissioner Jeanette Burns told Morning Report the department did recognise the risk Robertson posed, and used all the tools it had available to it.
No gaps or lapses in monitoring were identified in the Chief Probation Officer's report, said Ms Burns.
"We were working within the legislation that was available and we did increase the number of visits to [Robertson's] home as well as having him report into the centre. We visited him at agreed times but we also visited him randomly to do some extra checks on him."
Ms Burns said an armed guard was not an option available to the department under the legislation.
She said the extended supervision order that was to have taken effect soon after Mrs Gotingco's murder had very similar conditions to the regime Robertson was under and still would not have prevented her death.
Preventive detention criteria not met
When Robertson was sentenced in 2006, the Crown asked for preventive detention, but the judge declined.
Lawyers say his criminal history would not have met the criteria for preventive detention.
Whangarei-based parole lawyer Sue Earl said once his sentence was completed there were no laws that could have kept Robertson in prison.
And Ms Earl said no one could have predicted Robertson would go on to commit rape and murder.
"Even a person who has served a sentence of say two-and-a-half years for an indecent assault, fairly minor, there's no knowing or predicting that he may go on to commit a serious offence," she said. "The risk analysis done on people is not an exact science."
University of Auckland law professor Bill Hodge does not think radical changes need to be made in current laws, but said the ability to impose preventive detention after sentencing should be given serious consideration.
Robertson was wearing a GPS bracelet when he ran Blessie Gotingco down, then raped, strangled and stabbed her, dumping her body in a cemetery the next morning.
Lawyer Sue Earl said it was a smokescreen that GPS tracking kept the public safe.
"There's no evidence to suggest that GPS reduces reoffending or acts as a deterrent to offending, so for me the best system would be having a very good regular relationship with a skilled probation officer who is constantly monitoring in person, that person," she said.
Former probation officer and family violence network Shine head Jane Drumm said she wanted GPS extended to more ex-prisoners.
But she admitted it was not perfect, and nothing could protect the public from a dangerous criminal like Robertson.
"When someone is a violent, persistent offender, particularly when that's also sexual as well, I think it (GPS) does have limitations," she said.
"Obviously this person has spent quite a bit of time working out how he could avoid being detected easily.
"Unless you had an armed guard as well as GPS monitoring, I don't really see quite how, unfortunately, this situation could have been avoided."
Robertson will be sentenced on 6 August.
- 4 October, 2006: Robertson sentenced to eight years in prison for offending including abducting a girl under 12 for sex
- April 3, 2009 Supreme Court reject Robertson's appeal bid
- December 2013: Robertson released from prison
- 6 January 2014: Convicted for breaching release conditions by letting unapproved visitors stay in accommodation operated by the Prisoners Aid and Rehabilitation Society.
- 16 January 2014: Charged with a second breach of being in a public park
- 19 February 2014: Justice Wylie approves 10 year supervision order
- 25 May 2014 Robertson runs down Mrs Gotingco in his car, abducts her, rapes her and murders her.
- 26 May 2014: Robertson dumps Mrs Gotingco's body at the Eskdale cemetery
- 15 April 2015: Justice Winkelmann rules that evidence regarding GPS data can go before the jury
- 22 April 2015: Robertson ruled fit to stand trial, by three mental health practitioners. Justice Winkelmann finds Robertson has a personality disorder and post traumatic stress but is able to instruct lawyers
- 28 April 2015, 2015: Auckland High Court trial begins
- 29 April 2015: Robertson fires his legal team headed by Chris Wilkinson-Smith. Mr Wilkinson-Smith is appointed amicus - a lawyer to aid the court and act as go between for Justice Brewer and Robertson.
- 5 May 2015: Jury told that a registrar of the High Court in Auckland has written an article on the case but they are not to read it or anything else on the internet about the case.
- 22 May 2015: Robertson convicted for the rape and murder of Blessie Gotingco