Philip Polkinghorne trial: Pathologists could not determine method of death

Tuesday, 13 August 2024

Warning: The latest evidence in the Polkinghorne trial involves detailed evidence from a forensic pathologist and his autopsy results. Some readers may find the content distressing.

Two pathologists could not conclude whether Pauline Hanna died by hanging or as a result of being strangled, either manually or by the use of a ligature, the jury in the Polkinghorne trial heard on Tuesday.

Both said they also couldn’t say whether a belt was applied to Hanna’s neck after her death, or whether an impression found on her skin was the result of it being removed after she’d been discovered.

Philip Polkinghorne, a 71-year-old eye doctor, has denied murdering Hanna, his wife. She was found dead in the entranceway of their Remuera home on April 5, Easter Monday, in 2021. The trial is under way at the High Court in Auckland.

The Crown’s case is that Polkinghorne was living a double life, he had an obsession with sex and meth and was in a covert relationship with an escort in Sydney. It argues Polkinghorne murdered Hanna before staging their home to make it look like suicide.

Polkinghorne’s defence is that Hanna had a history of mental health issues, was on medication, was exhausted by work and tragically took her own life.

Homicide or suicide?

Forensic pathologist Dr Kilak Kesha gave evidence on Tuesday of his autopsy results after carrying out the post-mortem examination on Hanna the day after she died.

Kesha also visited the Remuera home on Easter Monday - the day Hanna died.

“There was an impression on the right side of the neck,” Kesha noticed while at the home.

Kesha ultimately concluded the cause of Hanna’s death was neck compression but couldn’t say whether she died by suicide, manual strangulation or ligature strangulation. He also didn’t disagree under cross-examination that there were a lack of defensive injuries to Hanna if there’d been a fatal assault.

Dr Martin Sage was later called by the Crown to review Kesha’s findings and concluded the same.

'At first pass this looks like a suicide… but the bit that bothers me most is that the assembly which she’s suspended herself doesn’t look like it's capable of doing that,' Dr Sage said.

He had to look at other alternatives.

'Perhaps the ligature has been tightened some other way, or something else has happened that’s incidental to her death,' Dr Sage said.

But ultimately, he couldn't tell whether it was a case of homicide or suicide.

Bruises and abrasions

Kesha took Dickey through his autopsy findings, including the various injuries to Hanna.

He said there were petechial haemorrhages on the inside of the lower eye lids. Petechial haemorrhages are small pinpoint red contusions that Kesha said are commonly seen when there is an obstruction to the neck veins.

There were also similar petechial haemorrhages inside the lower lip.

Kesha said Hanna’s tongue was also protruding which was common in hangings but also seen if someone has been strangled manually or by the use of a ligature.

In regards to the abrasions on Hanna's nose, Kesha said he couldn’t say what caused them.

Dickey asked if Kesha could age the abrasions.

“There was no evidence of any healing or scab formation on the injury so it was quite recent… all I can say at or around time of death,” Kesha said.

There were also red discolouration on her upper eyelids and a highly congested area of petechial haemorrhages, which was common when there was preclusion of the neck veins, Kesha said.

Kesha said there was a discolouration and abrasion to Hanna’s back, which most likely was caused by blunt impact.

“After death - your body starts going through changes, blood begins to pool in dependent parts of the body, if you die and lie on your back blood will pool towards your back,” Kesha said.

Kesha also noted several purple bruises on the back of the right arm. He said often this was seen if someone is held and fingermarks on the back of the hand, but said he couldn’t tell if this was the case on Hanna.

There was bruising at the base of the tongue, right side of the tongue and a bruising in a small piece of tissue in the neck above where a collar would sit.

The belt

The forensic pathologist said when he attended the Remuera home on the morning of Hanna’s death he noticed a criss-cross pattern on the right side of her neck going horizontally to her back.

“One of the police officers showed me a belt and the pattern looks identical.”

Polkinghorne told police he found Hanna with the belt around her neck that morning.

But the pathologist said this mark was not present at the post-mortem the following day.

Dickey asked what that suggested and Kesha said there was no bruising underneath the skin or to the muscles of the neck.

“There was an object, most likely the belt, on the neck after death,” Kesha said.

Dr Sage said from looking at the photos of Hanna’s neck, “it’s clear from that more than one turn to create the mark of that depth”.

Dr Sage said the mark was visible at the scene, but wasn't as clear when the post-mortem was conducted and was a 'remnant mark'.

Neck compression the cause of death

The pathologist said of interest to him was the toxicology.

“The zopiclone level (sleeping pill) was quite high, not lethal high but quite high… she was not prescribed zopiclone so I’m not sure where she got it from.”

A toxicologist previously gave evidence indicating Hanna had been taking zopiclone for six months.

Kesha said the cause of death was neck compression and this covered hangings, ligature and manual strangulation, self strangulation and auto-erotic asphyxia.

He said someone could lose consciousness in under 10 seconds, usually around 6, but needed to be around four minutes of continuous pressure for death.

In regards to the mark on the neck it was more consistent with a ligature strangulation given the angle.

“This appears to be ligature marking.”

However, Kesha said usually those who die by ligature strangulation put up a fight and there are a lot more injuries, including scratches to the neck, but during Hanna's post-mortem there were hardly any injuries.

Dickey asked if this was always the case.

Kesha said they weren’t always present if there’d been another way of subduing someone.

“It is clear something was on her neck and most likely removed shortly after death.”

Kesha said the markings were very consistent with a ligature strangulation or hanging but he couldn’t preclude manual strangulation, self strangulation or auto-erotic asphyxia.

Suicide couldn’t be ruled out

Under cross-examination, Ron Mansfield KC, questioned the pathologist on the fact his autopsy findings were entirely consistent with suicide by hanging.

Kesha didn’t disagree, but said he couldn’t rule out the other mechanisms.

“The impression on the neck is inconsistent with a hanging,” Kesha said.

But the pathologist agreed that the belt could have been removed 1-2 hours after she’d been discovered dead or place on Hanna’s neck after death. But he couldn’t specify which one.

The pathologist also agreed he would usually expect to find more injuries on a person if they’d died by manual strangulation or soft ligature.

In Kesha’s formal written statement, he told police it was difficult to know the mechanism that caused the neck compression but disagreed with Mansfield that he now preferred one mechanism over the other.

He said there was no indication there’d been a violent attack.

The trial, which is expected to last for at least 6 weeks, before Justice Graham Lang and a jury continues.