"The decision to accept a plea of manslaughter in substitution of a murder charge is never taken lightly. A robust process is followed, which ultimately requires the approval of the Solicitor-General. The overarching consideration is whether the interests of justice are met in accepting the plea, and in particular whether the charge can adequately reflect the criminal nature of the conduct as well as allow sufficient scope for sentencing.
"Based on the evidence available for trial, there was a substantial risk that one or both of the defendants would not be convicted of the legal charge of murder or manslaughter."
To prove the charge of murder, the Crown would have had to prove beyond reasonable doubt that Moko's fatal injuries were inflicted with murderous intent.
"The Crown was confident that Shailer was the principal offender, and most likely directly responsible for Moko's most serious injuries. The nature of Haerewa's involvement in Moko's fatal injuries was less clear on the evidence available for trial," Mr Finlayson said.
"It was relevant to the likelihood of securing a murder conviction that the injuries Moko suffered were not inevitably fatal. With reasonably prompt medical treatment, he could have been saved.
"Let me be clear, this in no way reduces the seriousness of the abuse Moko suffered. It is, however, something the jury would have had to take into account when deciding if Shailer had murderous intent at the time she inflicted the fatal injuries," he added.
"If the jury was not satisfied beyond a reasonable doubt that Shailer had murderous intent at the time she inflicted the fatal injuries, then neither she nor Haerewa could have been convicted of murder.
"Of course, the defendants also had a responsibility to obtain the medical treatment which would have saved Moko's life.
"By failing to discharge this duty, they contributed to his death in addition to causing his fatal injuries. But the failure to discharge this duty could not in itself lead to a murder conviction for both defendants. Nor would a conviction for manslaughter based solely on this failure have adequately reflected the defendants' role in inflicting the injuries that killed Moko."
The Solicitor-General had considered that accepting guilty pleas for manslaughter in substitution of murder charges meant that both Shailer and Haerewa admitted responsibility for inflicting the injuries that killed the child and their failure to obtain life-saving medical treatment; for him, and both could be given a sentence that reflected the serious nature of their crimes.
Haerewa had admitted that he had contributed to Moko's death by encouraging and supporting Shailer's physical abuse. In the absence of his guilty plea, his role in the violence that killed Moko may not have been adequately recognised in the ultimate outcome of a trial, however.
The guilty pleas also avoided exposing young, vulnerable children to the trauma of giving evidence, including, for some, evidence against their parents.
"There has been significant public interest in this case, and numerous statements have been made in the media about the charging of Tania Shailer and David Haerewa," Mr Finlayson added.
"The cost of prosecuting this trial was not a factor taken into account in approving the manslaughter charge. The public interest in prosecuting such serious crime would never take into account the financial cost of bringing a defendant to trial.
"Nor is plea bargaining a feature of the New Zealand justice system. Prosecutors cannot agree to a guilty plea based on the premise they will support a specific sentence."
