STORY CONTINUES AFTER LIVE BLOG
STORY CONTINUES
The crystalline methamphetamine that police found in Polkinghorne’s Remuera home shortly after his wife’s suspicious death is known for being especially potent and addictive, a psychiatrist specialising in addiction told jurors this morning at his ongoing murder trial.
Those who binge the drug might feel “aroused and alert and awake” at first, Dr Emma Schwarcz said, but as the binge continues the negative effects can take precedence: agitation, low mood and irritability.
“We know that violence is not an inevitable outcome of methamphetamine use,” she said. “We can say there’s a positive association... between aggression and methamphetamine use across the range of studies.”
Polkinghorne pleaded guilty at the outset of his Auckland High Court trial nearly four weeks ago to possession of the methamphetamine and a meth pipe found in the home, but he has insisted he was not responsible for his wife’s death. His lawyers have endeavoured through cross-examination of Crown witnesses to convince jurors that the case is an example of police overreach based in part on judgmental views on the couple’s open relationship lifestyle.
Hanna, the defence has argued, had suffered depression for decades and was dealing with more stress at work than ever before due to her role helping manage the rollout of the Covid-19 vaccine. Her death was exactly as it initially looked, a suicide, they said.
Schwarcz explained to jurors today that users who smoke crystalline meth get a large jolt in a short period.
”It causes this huge release, a profound release, of dopamine into the synapse,” she said.
Chocolate, she explained, might stimulate 100 units of dopamine, while cocaine can result in 300 units. But meth, she said, can result in up to 1200 units. And unlike other stimulants that wear off faster, the effects of methamphetamine can last 12-17 hours, she said.
She described people who use the drug as keyed-up and wide-eyed. They can become more talkative, confident, have a higher libido, and don’t want to sleep or eat, she said, but there is significant individual variation from person to person.
People with a meth use disorder are in a constantly dopamine-depleted state, so they might not be able to experience the normal amount of joy that they previously would, Schwarcz said.
People who become dependent on the drug are less able to fulfil their normal roles, whether it be professional or family, she said, adding that long-term use has been found to be “neuro-toxic”.
“It has significant impacts on the brain in the long term,” she said, describing a reduced brain mass and other “structural changes”.
Schwartz was also asked to review some of the many studies that have been done examining the link between meth use and aggression. One 2014 study she cited found a three-fold increased risk of violence for users of the drug and a 10-fold risk for heavy users. A New Zealand study looking at 1265 people born in New Zealand found that those who used the drug were 2.4 times more likely than their peers in the study to perpetrate violence even when accounting for background and upbringing. The risk of intimate partner violence was nearly doubled, she said.
But in the same New Zealand study, 78% of users “reported no aggression or violence whatsoever”, she added.
The drug “can profoundly impact behaviour” and can cause “departing from one’s moral norms and values”, she summarised as her direct examination under Crown Solicitor Alysha McClintock finished.
During cross-examination of the expert, defence lawyer Ron Mansfield KC noted that effects of the drug can depend on the dose and how frequently one uses the drug. Schwarcz agreed.
Mansfield has suggested his client’s use of the drug was infrequent and “recreational”. The Crown, meanwhile has argued it went beyond that. The 37g of the drug found in his house would have been the equivalent of 370 “points”, or doses, McClintock said during her opening address.
The defence lawyer also suggested today that increased violence among meth users may be linked to “lower socio-economic position”, leaving it unsaid that no one would mistake his client – worth $10 million – as someone in that position. Schwarcz said she was “worried about associating lack of employment and socio-economic disadvantage” with violence on drugs, but she noted that in some studies adverse childhood experiences can play a role.
“Certainly, from clinical experiences, a wide range of people can and do perpetrate violence,” she explained, adding that it can’t be “pigeon-holed into a certain demographic group and upbringing”.
Mansfield referred to a wastewater drug testing indicating that about 9200g of meth is being consumed weekly on average in Auckland. That’s an indication, he suggested to the expert, that the drug is used widely on a recreational level. Schwarcz disagreed.
Schwarcz said her understanding is the population prevalence of meth use is 1.1% to 1.3%. But the New Zealand study referred to earlier suggests 28% of participants had tried it at least once by the time they were 35.
Jurors also heard for third and final day from forensic accountant Margaret Skilton, who works for the police financial unit.
The accountant was briefly asked by the defence to go over the nearly $300,000 in transfers from Polkinghorne’s bank accounts to six different women – three of whom have been identified as sex workers – in the five years leading up to Hanna’s death. Jurors heard about the payments in detail yesterday.
Mansfield asked Skilton if she knew if any of the payments were loans or a gift, and she acknowledged she wouldn’t have that information based on the financial records she examined. The defence lawyer noted that there was one credit in Polkinghorne’s account of $6000 from a sex worker named Alaria. He asked the expert if she knew about her family’s financial or medical needs, and she again acknowledged she didn’t.
Prosecutor Brian Dickey later returned to the Alaria payment, asking the expert how much Polkinghorne would have paid the sex worker if the $6000 noted by the defence was to be credited. The payments still amounted to $55,800, she said.
There were no bank notes indicating Polkinghorne had business relationships with any of the women, she said.
Testimony is expected to continue this afternoon when the trial resumes before Justice Graham Lang and the jury.
Craig Kapitan is an Auckland-based journalist covering courts and justice. He joined the Herald in 2021 and has reported on courts since 2002 in three newsrooms in the US and New Zealand.
The Herald will be covering the case in a daily podcast, Accused: The Polkinghorne Trial. You can follow the podcast at iHeartRadio, Apple Podcasts, Spotify, through The Front Page feed, or wherever you get your podcasts.
