Two New Zealand pathologists who estimate they have conducted 14,000 post-mortem examinations between them over the course of their careers spent the majority of today in the witness box at Auckland eye surgeon Philip Polkinghorne’s ongoing murder trial.
But by the end of the day, jurors were left with few definitive answers other than an admittedly vague agreed-upon cause of Pauline Hanna’s death: neck compression.
The mechanism of the 63-year-old’s fatal neck compression might have been suicide by hanging, or she might have been strangled with hands or a ligature, Doctors Kilek Kesha and Martin Sage reckoned. It also might have been a chokehold-like manoeuvre sometimes used by police officers called a carotid hold, and auto-erotic asphyxiation could not be ruled out.
Prosecutors allege Polkinghorne, 71, fatally strangled Hanna before staging a suicide scene in the entryway to their Remuera home on the morning of April 5, 2021. The defence has noted she had battled depression for decades and has insisted there are logical explanations for each of the things that caused police to treat it as a suspicious death almost immediately.
While being questioned by Crown prosecutor Brian Dickey today, Kesha noted two strange things about a braided pattern found on the side of Hanna’s neck at the scene: Its angle and the disappearance of the impression by the time of Hanna’s autopsy the next day, roughly 20 hours later.
A belt matching the pattern was found rolled up in the kitchen of the couple’s home. Polkinghorne said in a police interview that he had found the item around his wife’s neck but had removed it before police arrived because it was too grotesque.
The disappearing “criss-cross pattern”, Kesha told jurors, might suggest “that there was an object on the neck after death” - potentially giving credence to the Crown’s suggestion of a staged suicide.
“It’s clear there’s something on her neck,” he later explained. “Most likely it’s been removed shortly after death.”
As for the angle of the pattern, Kesha said he would have expected it to be in a diagonal direction across her neck had she died via hanging. A straight line impression, as viewed at the scene, would be more indicative of someone pulling a ligature from behind, he opined.
If jurors might have been initially left with the impression that a suicide by hanging was the least favoured of the pathologist’s theories due to the belt mark, Kesha left a quite different impression during his cross-examination.
“Is it right to say your findings were entirely consistent with suicide by hanging, namely an incomplete or partial hanging?” defence lawyer Ron Mansfield KC asked at the outset of his questioning.
“No,” Kesha said, before clarifying: “It can be.”
The defence lawyer suggested that the belt mark might be there initially but disappear if it was used in a hanging but then removed between an hour or so after death. The pathologist agreed.
“These possibilities are equal, aren’t they?” Mansfield said of the theories that the belt was either applied after death or there during death and removed within two hours. The pathologist again agreed.
So the jury shouldn’t put “undue weight” on the disappearance of the mark between April 5 and the autopsy the next day, Mansfield suggested and Kesha agreed.
But Kesha wouldn’t go as far as agreeing with the defence that he didn’t find the disappearance of the mark or its alignment on the neck “at all significant”. He might not have mentioned the disappearance in reports but had mentioned it to police who were present during the post-mortem, he said.
“I think it’s relevant,” Kesha said, as he was asked the question several times.
Kesha was also asked by the Crown and the defence about the lack of major injuries on Hanna, which he confirmed was “significant” - unusual but not unheard of for someone strangled in an assault. Dickey, for the Crown, pointed out that a person can be made unconscious after less than 10 seconds of consistent pressure. But Kesha noted it hardly ever happens that way in real life.
“Most of the time when someone is strangled, the pressure is not consistent,” he explained. “They’re putting up a fight. This fighting could go on for quite some time.”
Mansfield later suggested that to cause a person to lose consciousness without injury would take a professional - like a police officer or SAS member - experienced in carotid holds. The defence lawyer also noted that Hanna did not suffer a strap muscle haemorrhage, which is common in chokeholds or manual strangulations but not often seen in suicides by hanging. The pathologist agreed the finding was “significant”.
Kesha, who operates out of Auckland Hospital, was followed on the witness stand by Sage, a colleague from Christchurch who was asked to review the post-mortem report and findings. Sage, who has been conducting autopsies for criminal investigations for 35 years, estimated that he has handled roughly 800 hanging cases.
“I’ve seen a lot of hangings, but I haven’t quite seen it like this,” he said of the disappearing neck mark.
He took issue with the way the defence presented some questions to Kesha, noting that he and his colleague were often being asked if the findings were “consistent with” a suicide. That term has been “condemned” by courts in recent years because it can be vague and misleading, Sage asserted, adding that he was reluctant to go along with anything put to him in those terms.
Sage’s answers were much the same as his colleague’s, but he pushed back more when it was suggested by the defence that the autopsy findings amounted to evidence in favour of suicide.
For example, you’d expect to see bruising around the neck if it was a manual strangulation and there was none in this case, he conceded. But that doesn’t mean it’s impossible to have strangulation without bruising, he said, noting that such cases would be more likely to go unnoticed and therefore be less documented. He noted that some serial killers in the United States claim they’ve found a way of doing so without leaving marks, but added: “What faith we can put in that commentary, I don’t know”.
“It’s terribly inconvenient” when injuries aren’t found, he said, “but the absence [of injuries] doesn’t prove if it happened”.
The defence is likely to call a third pathologist later in the trial: Stephen Cordner from Australia. Mansfield referred to Corner’s own 100-page report throughout today’s cross-examination. Sage said he disagreed with the report’s ultimate finding.
“He certainly decided that this all looks like a hanging ... and then doesn’t adequately, I think, explain the alternative explanations,” he said. “I think the court needs to hear further, other alternatives.”
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.