Two heinous crimes, one common denominator: Meth

On Friday morning, Julie-Ann Torrance wiped away tears as the High Court in Auckland heard how she helped brutally torture and kidnap an Auckland teenager. 

She sat alongside Nicola Jones and Wayne Blackett who had also played a part of the crime that became known as 'The Dome Valley case'. 

The trio were all handed down jail terms exceeding 10 years. 

Down the hallway, Jaden Lee Stroobant was being sentenced to preventive detention for the sexual violation and murder of his neighbour, Cun Xiu Tian, in January 2016. 

Two separate cases joined at the hip by one thing - methamphetamine. 

Defence lawyers on Friday morning outlined how the drug had ruined their clients. 

Stroobant's lawyer Emma Priest said he was an active drug user and had consumed a cocktail of drugs in the days leading up to the murder, including P.

Torrance, Blackett and Jones' lawyers all said the trio had been under the influence when they committed acts so bad, some have never been reported. 

Before the heinous crimes Jones had one conviction - for a driving offence.

"That doesn't even share an inkling of a resemblance for what we have before the court today," Jones' lawyer Maria Pecotic said.

"Those actions were of someone who had not slept for five days, and was utterly under the influence of methamphetamine," she said. 

It seemed all were mild-mannered people who were pushed over the edge. 

But is it meth or madness which causes people to commit heinous crimes? 

"It is not the meth which causes the behaviour, it is the lack of empathy," drug and alcohol counsellor Roger Brooking said. 

"It may facilitate bad behaviour, but it does not necessarily cause it." 

Brooking rubbishes the myth meth will turn even a middle-class soccer mum into a murderer. 

Instead, he believes, it brings out the bad. If you're already likely to become violent, then meth will help you along the way. 

"Meth is probably not going to make you a monster.

"If somebody is already emotionally disregulated or has anti-social personality disorders, and you add meth into the mix, it is going to facilitate aggressive or violent responses."

The biggest danger methamphetamine often poses is not violence, but addiction.

"If the addiction takes over, which is frequently does, the person's ability to hold down a job becomes diminished. A lot of people who become addicted to meth eventually start dealing it to fund their habit." 

The devil is in the detail when it comes to addiction, according to Brooking. Often the trigger for addiction is tied to the cause of committing a crime. 

"They are using one substance or another to alleviate painful or distressing feelings, thoughts or images that they have been exposed to in their childhood.

"It anaesthetises the users ability to feel their own distress. So they kind of keep going as they can suppress, ignore or anaesthetise their pain."

In the Dome Valley sentencing, Justice Whata noted how all defendants had suffered challenging childhoods which had left them struggling. 

The sad thing, according to Brooking, is that some meth users only fully realise their actions after they break their addictive cycle. 

"People with an addiction will end up looking back on it and think, 'Oh my god, why did I get into that?'" 

The four sentenced on Friday will have a long time to ponder that question.