The manipulations of Aaron John Ellmers were a carefully designed betrayal of trust.
He planned and plotted ways to steal children away from their parents so he could abuse them and then trade images of his crimes worldwide.
The most sickening breach of trust was his last - he found a father willing to rent out his 13-month-old son for Ellmers' perverse use for the price of $500.
As the 40-year-old paedophile jetted into Christchurch to meet the baby's father, police were waiting.
The Hastings man yesterday pleaded guilty in the Hastings District Court to dozens of charges associated with abusing four children, aged 13 months to 13 years.
The father, aged 27, was also arrested. Also facing charges is an Auckland man who received images from Ellmers with pictures of his abuse.
The specialist police team which first identified Ellmers (Oceanz - Online Child Exploitation Across New Zealand) has also passed on 35 separate sets of details to law enforcement agencies around the world, traced through the illicit online traffic of the men facing charges.
Detective Senior-Sergeant John Michael said he hoped it would be enough to stop images of the four Kiwi children Ellmers photographed and filmed himself abusing from joining the international traffic in child pornography.
It could also be that the chance to stop the spread of images and footage had gone. "We can identify the first points ... subsequent ones - we won't be able to identify them."
Ellmers was convicted in Australia of raping an 8-year-old boy. Deported in 2008 after 18 months inside, he later told detectives the prison sex offenders' course gave him new tools which he used to coerce children to his will.
Ellmers wasted no time, according to court documents. In a conversation recorded in a Christchurch motel room in October last year, as he waited for a baby to abuse, he spoke of a friend's 7-year-old boy to whom he had had access since 2008.
"He explained that the father trusts him with the boy," the court record said, before detailing awful abuse which had taken place since the boy was 3.
Police recovered footage showing the abuse, which was emailed to the man in Auckland facing charges. In some footage, the boy was not conscious, having been drugged.
It took a long time to get a father's trust, Ellmers was recorded saying, detailing how he lurked on children's online chat groups.
He detailed how to manipulate children's trust, how the games of childhood could be perverted to a paedophile's advantage.
In the case of the 13-month-old he travelled to Christchurch for, the father was no obstacle but an accused fellow abuser he met online.
Court documents show police found Ellmers had collected and traded thousands of images and movies of children being abused.
Mr Michael said images of fresh victims were valuable currency in the international sex trade in children.
"There are images out there and movies out there that have been circulated for a long time. What keeps it going is the demand for new material."
He said the case showed the extraordinary steps some would take to secure children for abuse.
"If we look at the warning message to parents, it is 'don't be alarmed by this but be alert for suspicious behaviour'."
He accepted Kiwis might be surprised at the existence of domestic victims, as was he when he set up the unit in 2009.
"I wondered when we would get to New Zealand victims."
In fact, it took little time.
Ellmers' sentencing was transferred to the High Court, with Crown prosecutor Steve Manning saying his abuse was at the "highest end of child sexual offending in this country".
Only the High Court can impose a sentence of preventive detention. That would mean Ellmers would be sentenced to a minimum term, and only released thereafter if authorities were satisfied he no longer represented a significant risk to the public.