A damning report has criticised the police investigation into contact between a teacher and the 13-year-old girl with whom he exchanged thousands of text messages in the year before she took her life.
An Independent Police Conduct Authority investigation found there was a failure to properly assess evidence, leads which were not followed, a conflict of interest which was not managed and inadequate supervision of the inquiry.
It also found a failure to manage and record interviews with Reiha McLelland, 13, or her former Gisborne Intermediate teacher Sam Back.
Former Gisborne detective sergeant Theo Ackroyd caught much of the criticism - he was supervisor of the child protection team while also leading the school board of trustees where the teacher worked.
Reiha's story
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The police investigation into the intense, secretive contact between Reiha and Back was investigated by the IPCA after a complaint by her parents.
Reiha died in August 2014 from self-inflicted injuries. She was 13.
Her death followed the painful withdrawal from an intense six-month relationship with Back, with whom she had exchanged more than 4000 text messages in three months.
It also emerged she had misled her parents to create opportunities to stay the night at the house Back shared with his partner Angie Mepham, also a teacher.
No evidence emerged the relationship had become physical although the messages included many in which Back referred to Reiha as "darling".
Examples in the IPCA report included Back texting Reiha late in the evening to say: "I so badly want to climb in your window right now. Just jump through and tell you that I am so glad that you are here, that you always, no matter what, you bring a smile to my face and joy to my life."
IPCA chairman Judge Colin Doherty said the content of the text messages should have lead to a deeper investigation rather than the assessment they closed inquiry doors because there were no specific sexual references.
Doherty said: "While no explicitly sexual language was used, the messages had obvious sexual overtones."
He said the evidence available should have led the trainee detective assigned to the case to seek expert advice about Back's behaviour.
Doing so would have "explored the possible need for further proactive enquires to establish if there had been any contact of this nature by Mr Back with other children".
Doherty said the pathways could have emerged if the investigation had adequate supervision.
While critical of the investigation, the IPCA found the case was properly assigned and its outcome was not predetermined.
The "recurring deficiencies on the investigation file" were related to "an inadequately managed conflict of interest and poor recording of information", he said.
Ackroyd's role in his police and school roles came in for significant criticism by the IPCA, with a focus on a letter he wrote to the Education Council nine months after Reiha had died.
At that time - May 2015 - Back and Mepham were facing professional charges before the Education Council.
As school chairman, Ackroyd wrote to the Education Council asking Back be given name suppression.
Among the reasons he cited was the possible impact publication of his name could have on any future criminal charges which could be laid - even though police had found there was nothing to charge Back with in June the previous year.
Ackroyd told the IPCA: "All that comment was about was there potential because who knows, they might come up with something else or keep the diaries or whatever."
The IPCA said Ackroyd's submissions to the Education Council were "patently wrong and misleading".
His action in doing so was "contrary to police policy and amounted to misconduct at the serious end of the spectrum".
It was such a serious misstep it could have resulted in the police officer facing criminal charges, said the IPCA's Doherty.
"If the supervisor had intended to mislead the Teachers Council, he would have been guilty of the offence of attempting to pervert the course of justice. However, such an intent cannot be proved."
The handling of the police investigation into Back's relationship with Reiha was one focus of the coroner's inquiry.
Ackroyd had maintained he had distanced himself from the inquiry because of the conflict of interest, although he still featured in documentation and decisions around whether inquiries should continue.
The IPCA report studied whether the outcome of the police inquiry was predetermined and quoted Ackroyd saying: "I wasn't mates with the teacher … I wasn't friendly with him ... I pride myself on being objective and if it meant the guy went to prison, he went to prison.
"An investigation had to take place. If there was evidence to support a conviction then so be it."
The lawyer for the McLelland family, Moira Macnab, said the IPCA report showed "serious deficiencies" with the police handling of the case.
"It finds that the investigation was not properly supervised and that the investigation was inadequate."
Macnab said the report showed police had not made all inquiries which should have been made, that there were lapses in recording of information and that there was a conflict of interest.
She said submissions by Ackroyd to the Education Council had been shown to be misleading and contrary to police policy.
Macnab said the IPCA report showed a lack of clarity as to how police were handling the complaint about Back's contact with Reiha, which was concerning given the thousands of text messages exchanged between the two.
She said "any normal person" would view the "repugnant" text messages and realise there was a serious child protection issue at stake.
Macnab said the investigation should have sought access to Back's computer and delved deeper into finding who placed calls to Reiha's mobile phone in the lead up to her death.
Evidence had shown there were calls to her phone with caller identification withheld.
"There will always be questions over what she had been told (in those calls). This is especially the case since Reiha had written that she would take her life to protect Mr Back."
Eastern District Commander Superintendent Tania Kura said police got a number of aspects wrong.
She said the sincerity of the trainee detective assigned to the inquiry was not in question - he was "committed to obtaining the best outcome he could".
"However, it is very clear that there were a number of issues with how the investigation was carried out, including a lack of supervision, inadequate assessment and recording of evidence, and inappropriate management of a conflict of interest."
She said an internal review had found similar faults.
"We have to be better than this."
Kura paid tribute to the McLelland family and their loss.
"It has been four years since Reiha's tragic death and I'm sure the pain of her family and friends has not diminished in that time."
After the relationship between Back and Reiha was discovered, Gisborne Intermediate initially censured Back but allowed him to continue teaching. The school's obligatory notification to the Education Council, which hears cases of teacher misconduct, came about the same time as a formal complaint from the McLellands.
The council investigated and both Back and Mepham were found guilty of serious misconduct. He was struck off as a teacher while she was censured but allowed to continue teaching.
Back has always maintained he wanted the best for Reiha and was maintaining contact to support her.
2013
February: Reiha goes into Sam Back's Year 8 class at Gisborne Intermediate.
September: Back and Reiha begin communicating outside of school.
October: Reiha stays the night at the house Back shares with partner Angie Mepham - the first of many times she stayed over.
2014
April: Concerns about Reiha's well-being lead to text messaging with Back being discovered. Police are called.
June: Police inquiry finished - no charges.
July: On the last day of the month, Reiha inflicted unsurvivable injuries on herself.
August: Life support is removed from Reiha.
2016
June: Police complete a secret review of its handling of the investigation into Back.
September: Inquest into Reiha's death begins.
December: With intermittent hearings, the inquest finishes.
2017
June: Coroner Carla na Nagara issues her ruling. She does not find Reiha's death was Back's fault but says his relationship with Reiha was the "primary stressor to Reiha in the last three months of her life".
2018
December: The IPCA releases a report, critical of police on a number of counts.
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