* Warning: This court report contains details that some may find upsetting.
A jury has watched CCTV images of what appears to be a Dunedin doctor's car heading towards a teen's house the night she was murdered.
Venod Skantha, a doctor, is on trial in the High Court at Dunedin for the murder of Amber-Rose Rush, 16, in her bed in February last year.
The Crown believes Skantha asked a teenage friend to drive him to Amber-Roses' house in his silver BMW. It is alleged he killed the teen to silence her after she threatened to tell police and his hospital bosses about providing teens with alcohol and drugs.
CCTV images presented as evidence today show a car driving down South Rd from the Caversham direction shortly before midnight.
It's seen heading back the way it came seven minutes later.
Amber-Rose died within minutes of stabbing: Pathologist
Amber-Rose would have taken "some minutes" to die from her wounds, a pathologist told the court earlier today.
Skantha, 32, has pleaded not guilty to the murder of Amber-Rose Rush and four other charges of threatening to kill at the outset of his trial before the High Court at Dunedin this week.
The Crown told the jury in the opening address that the doctor had been messaging the 16-year-old victim only minutes before her death at her home in Dunedin, late on February 2 last year.
Amber-Rose told him she was planning to tell police and Dunedin Hospital bosses that Skantha had sexually assaulted her and others, and that he was supplying alcohol to minors.
"I'm doing the world a favour," she wrote. "People like you don't deserve to walk freely."
The Crown says Skantha found out Amber-Rose had posted screenshots of their conversation on social media and he then recruited a teenage friend to drive him to the girl's Corstorphine home.
The defendant allegedly used a spare key to get inside, then stabbed her six times in the neck while she lay in her bed, taking her cell phone and leaving her to die.
Forensic pathologist Dr Kate White gave evidence at court today. She completed her autopsy on February 5, 2018 and found that Amber-Rose died "as a result of an incised wound to the left side of the neck".
The injury that caused her to bleed to death sliced through her earlobe and hit the base of her skull.
Dr White told the jury the 11cm-long wound hit her carotid artery and breached the windpipe too. Due to its length, it was not a "classic stab wound", she said.
Crown prosecutor Robin Bates cautioned the jurors before providing them with photo booklets depicting Amber-Rose's body.
He asked the pathologist how much force would likely have been required to cause such damage.
"It's a very difficult question to answer and there's no way of precisely answering that," Dr White said.
She told the court the damage to bone suggested at least moderate force, but that also depended on the sharpness of the knife used.
The severance of the carotid artery, which takes a large volume of blood to the brain, meant the victim would have ultimately "bled out" without medical attention.
How long would it have taken? Mr Bates asked.
"Some minutes," said Dr White.
As well as the fatal injury, she also identified stab wounds to the back of the neck and two "superficial" horizontal cuts to the girl's throat.
None of those would have contributed materially to her death, the pathologist said.
• Dunedin doctor murder trial: Accused discussed potential suspects with victim's mum: witness
• Dunedin doctor murder trial: Accused Venod Skantha killed teen Amber-Rose Rush to protect his career: Crown
• Dunedin doctor Venod Skantha on trial for murder of Dunedin teen Amber-Rose Rush
• Murder trial: Doctor Venod Skantha accused of killing Dunedin teen Amber-Rose Rush
In cross-examination, Jonathan Eaton, QC, asked whether the witness could determine whether the killer was right or left-handed.
It was "notoriously unreliable" to speculate on that, Dr White said.
She explained she did not measure the depth of the wounds because it was not a reliable way of estimating the length of the blade used to create them.
She had not examined any weapon which allegedly caused the injuries.
Yesterday the jury heard how Skantha allegedly toasted marshmallows while burning the bloody clothes he wore to commit the murder.
Later, his ex-girlfriend said, they met Amber-Rose's grieving mother Lisa Ann Mills and bought her flowers and a card before suggesting who may have been responsible for her death.
Accused suggested Amber-Rose's death a suicide
Less than two days after allegedly stabbing Amber-Rose to death, Skantha had suggested to her mother it was probably a suicide, the court was told yesterday.
When Amber-Rose's mother, Lisa Ann, ''vehemently'' denied that was the case, the accused raised the names of a few people who might be involved.
The 32-year-old is on trial for murder and four counts of threatening to kill, before the High Court at Dunedin, where yesterday's evidence was dominated by the defendant's ex-girlfriend, Balclutha lawyer Brigid Clinton.
Though the pair had broken up months earlier, she had planned to see Skantha on the evening of February 2 last year for him to sign some legal papers.
However, he did not show up at her home as planned.
The Crown said Skantha was involved in a heated online exchange with Amber-Rose that night which ended with her confirming she was going to tell police and his hospital bosses that he had sexually assaulted her.
Prosecutors said the desire to silence her resulted in the defendant requesting a ride to the girl's Corstorphine home from his teenage friend, then stabbing the victim six times as she lay in her bed around midnight.
Skantha and the teen - who has name suppression - later drove to Ms Clinton's house.
About 1am she received a message saying he had been asleep and was now coming over.
Ms Clinton told him not to.
She was ''done with him, done with it'', she said.
However, an hour later, Skantha arrived at the house along with his 16-year-old associate.
They all went to bed and the next day visited The Warehouse.
''Venod mentioned having a bonfire; something to do,'' Ms Clinton said.
Skantha bought a large terracotta pot and lit a fire in it in the back yard while Clinton returned to the store.
''Venod said he was burning his daggiest clothes,'' she told the court.
They consisted of a charcoal grey jumper he wore around the house and a pair of light grey sweat pants, he told her.
The Crown told the jury at the trial's outset that the garments being burned were the clothes covered in Amber-Rose's blood.
Ms Clinton said she sat and talked to Skantha while they toasted marshmallows over the flames.
The ashes were later tossed into the garden, the witness said.
After spending a couple of nights in Balclutha, the defendant's teenage friend got a call from Amber-Rose's mother.
She wanted to speak to anyone who had had contact with her daughter.
They decided to visit Ms Rush in the hotel at which she was staying but they stopped at New World on the way - the supermarket where Amber-Rose had formerly worked.
Skantha bought flowers and a card for the grieving mother, along with a couple of bottles of wine for himself.
''Lisa was obviously really upset ... pale, in shock,'' Ms Clinton told the court.
''I remember Venod was sat next to her and suggested it was a suicide, to which she vehemently said no.''
There was then a discussion about potential suspects, she said, before they left.
On the way back to Skantha's Fairfield address, they dropped the teen at home.
Defence counsel Jonathan Eaton QC asked Ms Clinton whether she had heard any whispering between the defendant and his mate as she drove.
She had not.
The teenager had made a statement to police that Skantha had quietly said, ''No word or I'll kill you'', then laughed and shook his hand, before he got out, Mr Eaton said.
Ms Clinton said she had not heard such a conversation.
Back home, the woman said her ex-partner seemed in an ''irritated, almost indignant'' mood and was receiving numerous alerts on his phone.
He asked her to retrieve his samurai sword.
While ''waving it around above himself'', Skantha cut his finger and Ms Clinton took him to the urgent doctor to be stitched up.
Unbeknown to them, police had been tailing them throughout the afternoon and as they left the medical centre, officers pulled them over and they were separated for interview.
''I was in shock,'' she said, after being told of the allegations.
The trial continues.
- Additional reporting: Otago Daily Times