The elaborate web created by undercover police to catch double murderer Kamal Reddy can now be revealed.
The killer, behind the so-called "bodies under the bridge" murders, was drawn into a trap constructed by officers over six months. Finally, on October 14, 2014, he confessed to strangling his partner Pakeeza Yusuf with the cord of an electric iron, and smothering her 3-year-old daughter Juwairiyah "Jojo"Kalim.
• Kamal Reddy: Timeline to catch a killer
The confession was the key piece of evidence that saw him convicted of both murders at an Auckland High Court trial last month. Today he was jailed for life with a minimum of 21 years.
How was Kamal Reddy caught?
Undercover officers spent months posing as a gang going through the process of recruiting Reddy as a member.
Police used what they call the "Mr Big" technique, used more extensively in Canada and Australia.
They gained Reddy's trust through a series of staged crimes which increased in scale and seriousness, as the defendant became convinced he was part of a successful, organised crime syndicate.
Reddy, 43, primarily worked with one undercover officer - whose real name and code name are suppressed - who appeared to be a senior member of the group.
At the climax of the intricately planned six-month operation, he was sat down by the man purporting to be the boss and over the course of two interviews made stunning confessions which led to the bodies of his two victims being found under a Takapuna motorway bridge in 2014.
An elaborate trap
It took police more than a month to get Reddy on the hook.
Initially, Reddy was targeted at his home by a female undercover officer pretending to be conducting market research into internet service providers.
Later she called Reddy to advise him he was the lucky winner of an off-road experience in Rotorua, but he thought it was a scam and declined the offer.
They offered him a fishing trip too, but he would not budge.
It was only when they asked Reddy, a trained mechanic, to do some work on a car that they finally found a way in.
While his involvement began with low-level debt collecting, before long the killer and the cop were travelling around the country handling stolen goods, selling class-B drugs and the like.
On one occasion, when the pair were in Rotorua, Reddy was instructed to give $500 to an officer posing as a hacker in exchange for a hard drive purporting to hold "illicitly-obtained government information".
But as the defendant and his partner left the scene they were pulled over by a marked police car - a scenario carefully jacked up beforehand.
The officer searched the car and confiscated the hard drive. But then, while he checked the men's details, Reddy's partner called gang bosses who supposedly pulled strings with the group's corrupt police contacts.
Minutes later the officer let them go, escaping what had appeared to be certain arrest.
"I don't know who you are or what's going on but I've been ordered to let you go," the cop told them, with acting so convincing defence lawyer Jonathan Krebs compared it to Liam Neeson.
Like all exchanges when Reddy was with his undercover handler, it was recorded on hidden devices in the car and on the operative himself.
This incident was selected, among others, from the hundreds of hours of secretly-recorded conversations and provided compelling evidence for the jury, not to mention courtroom drama.
Reddy was also tasked with the disposal of police evidence, which was handed over by seemingly crooked cops in return for large cash sums.
In one such scenario in Wellington, just a week before his confession, he and his undercover handler obtained a police DVD and clothing after one of their group was accused of having sex with an underage girl.
The pair went to Bunnings for supplies before driving to a "discrete location" to burn the items.
The incident was designed to demonstrate to Reddy just how powerful the gang was and that ultimately, he could trust them. Reddy was being drawn in, seduced by the idea of working for and belonging to the gang.
And it worked.
Reddy's temptation: 'Trust us'
But the question of how to get Reddy to open up about his relationship with Ms Yusuf, aged 33 when she was killed, was one that loomed large.
There was no doubt he believed the police's set-up was legitimate - but they were a long way from getting a confession.
Regular briefings between his handler and bosses of the police's undercover programme were all aimed at ultimately uncovering whether the man had a role in the victims' disappearance.
But they could not risk blowing the whole investigation by simply asking him.
It took a carefully orchestrated scenario before Reddy opened up about his past relationship with Ms Yusuf.
While he and his undercover buddy were driving through Wellington on October 10, 2014, they were forced to stop while someone crossed the road.
The man on the pedestrian crossing was Detective David Sanday, who had previously questioned Reddy about the victims' disappearance in Auckland months earlier.
Soon after, he pulled the men over and it inevitably sparked a conversation during which Reddy had to bring up his link to the missing females.
Gradually, over half a year, the principles of the gang were drummed home to the defendant.
"Trust, honesty and loyalty." The gang's boss - its Mr Big - was painted as an uncompromising businessman but one who above all else appreciated honesty from those working for him.
Reddy's handler took every opportunity to stress that and even had his own story.
He told the suspect how in a previous job he had stolen a significant sum of money and though he knew he could never be caught, he came clean to the boss.
And he got more respect because of it, he told Reddy.
Why Reddy confessed to murder
Four days after bumping into Detective Sanday, the 43-year-old sat down with the man posing as the big boss in a plush Wellington apartment.
It was apparently a chance to discuss Reddy's future but despite having all the hallmarks was "not a job interview" according to the man.
He had heard plenty of good things about "Kam" but one thing had come to his attention that troubled him - some rumblings about his connection to two missing people.
The boss wanted to know the truth so if there was a risk to the group as a whole he could "put a plan in place".
It was nothing, Reddy told him, just an old flame who had gone from his life years ago.
After just over an hour of gentle probing, the boss let him go for lunch.
But while they tucked into their KFC, Reddy's handler revealed the boss was not buying his story of innocence.
They had heard he was the prime suspect in a murder case.
When Reddy was returned to the flat shortly afterwards to sit down with the boss again, he was noticeably more sheepish.
A secret recording played for the jury showed him hunched over as he sat on the couch - a complete contrast from hours earlier where he beamed about enjoying the work he was doing for the organisation.
Over the following two hours he told his prospective employer how he had killed the mother and daughter, buried their bodies under a North Shore motorway bridge and systematically disposed of their belongings in skips and clothing bins around the city.
The final chapter
It was a relief to finally tell someone, he said.
But his description of the location was vague. The police needed more.
And so days later he drove up and down State Highway 1 with an undercover officer before it finally clicked for Reddy. He recalled the location of the bodies as they passed Takapuna.
The pair scaled the bank leading down to the huge concrete pillars holding up the bridge.
"So just go and stand where you reckon the middle of the hole will be," the handler said. And Reddy did.
A photo of him standing on the burial site taken by the undercover cop was almost all the evidence the police needed.
Even when Reddy was arrested and charged with the murders days afterwards, he had no idea he had been snared by an elaborate sting.
He asked police if he could speak to the undercover officer who had spent the last six months gaining his trust.
Instead of bringing him a phone, Manukau police officers brought him a device which held a 21-second recording in which the cop made his own confession.
"Hi Kamal, this is [X] here. [X] isn't my real name. I'm actually an undercover police officer and I've been working with you for a number of months now in relation to the disappearance of Pakeeza and Jojo."
"MR BIG" UNDERCOVER TECHNIQUE
• The suspect is introduced to an undercover officer who spends time gaining his trust.
• He/she is invited to participate in staged criminal activities with the officer.
• It is designed to show he/she is working with a successful criminal organisation.
• The suspect is introduced to other undercover officers, posing as gang members or associates, throughout the operation.
• There is a "Big boss" at the head of the organisation who eventually has the role of inducing the truth from the suspect.
• The technique originated in Canada and has been used in Australia too.
• It must be authorised at the most senior levels within the police force and must only be used as "a last resort" when other investigative options have been exhausted.