[2] In July 2012, a coroner's report was released, which concluded that the children's injuries occurred "whilst they were in the sole custody, care and control of their father".
[4] However, the relationship was not always smooth, with a range of risk factors contributing to tension and instability for the couple prior to, and after, the arrival of their children.
[5] After their birth, Cris and Cru spent six weeks at the Kidz First neonatal intensive care unit at Middlemore Hospital.
On 13 June 2006, upon returning home after a night of partying, King found that the twins suffered extensive bruises and that their grandfather, William "Banjo" Kahui, had performed cardiopulmonary resuscitation on them.
According to former MP John Tamihere, members of Chris Kahui's extended family had said "a young relative", whom they refused to name, was caring for the infants on the day they were fatally injured.
An orthopaedic specialist told The Sunday Star-Times that in order to break the femur of a baby, the bone would have to be deliberately bent at a 90-degree angle, ruling out an accidental cause of the injury.
CYF removed Shane and their female cousin Cayenne, aged six months, from two rented Housing New Zealand homes – one in Clendon and the other in Māngere — where Cris and Cru had lived.
[12] The deaths of Cris and Cru resulted in an initial serious assault investigation by the New Zealand Police before charges were upgraded to homicide.
[16] Following the deaths, Sharples said he was disgusted by the Kahui family's behaviour, claiming some of them were more interested in going "to the pub and have a drink" than coming forward to police.
[20] By 4 July, at least twenty extended family members were questioned, as well as ninety medical practitioners and staff who were in contact with the twins.
[26] The infants' paternal grandmother, who appeared the next day on TV3's Campbell Live, contradicted this information, stating that the killer was female.
One neighbour said that a sixteen-year-old female appeared on their doorstep at 3:30 a.m. one morning after she said an older man at the Clendon house attempted to sexually assault her.
At 10 p.m., it was announced in a press conference that a 21-year-old man had been arrested and charged with the murder of the infants, and would appear in the Manukau District Court the next day.
[34] Three weeks later the Sunday News said four people involved in the investigation had been summoned to appear at the Manukau District Court on 24 January.
The officer who led the police investigations into the murders, Detective Inspector John Tims, said he was "disappointed" at the verdict,[43] finding "no evidence to support a charge against any other person and that includes the mother, Macsyna King".
[44] Tims acknowledged the prosecutor, who had "said in his opening and closing address that there is no new evidence to support a charge being laid against the mother, Macsyna King".
He found that the twins had suffered the brain injuries which led to their deaths during the afternoon or early evening of 12 June 2006, at a time "whilst they were in the sole custody, care and control of their father", Kahui.
[46] The case highlighted the fact that Māori children are more than twice as likely to die as a result of abuse than non-Māori[47] and that New Zealand ranks fifth highest among OECD nations for child deaths due to maltreatment according to a 2003 UNICEF report.