The jury in the High Court trial of Venod Skantha has retired to decide the former Dunedin doctor's guilt.
Venod Skantha Photo: RNZ / Tim Brown
The 32-year-old denies murdering 16-year-old Amber-Rose Rush on 2 February last year.
Mr Skantha is also accused of threatening to kill the prosecution's key witness and his family.
Justice Gerald Nation summed up the case for the jury of ten men and two women this morning, before the jury retired shortly before 2.45pm to deliberate its verdicts.
Justice Nation said the jury needed to decide, beyond reasonable doubt, who wielded the knife that ended Miss Rush's life.
"It is common ground that when Amber-Rose Rush was on her bed, someone cut into her neck with a sharp instrument causing her to bleed to death," he said.
"To cut someone's neck in the way that happened is an unlawful act and the person who cut her neck must have intended to kill her.
"The real issue is whether you are satisfied beyond reasonable doubt that Dr Skantha was the who killed Amber-Rose Rush. If you are you will find Dr Skantha guilty of murder."
The judge instructed the jurors to set aside any feelings of sympathy or prejudice towards any of the people involved in the case and exercise their common sense in assessing the evidence presented during the trial.
The Crown says Mr Skantha murdered Miss Rush to stop her coming forward with claims he was "touching up" minors, supplying them alcohol and offering money for sex.
The defence says the prosecution's key witness, a teenager with name suppression, killed Miss Rush.
Both sides set out their final arguments yesterday.
Prosecution's case
Crown prosecutor Robin Bates said the collective strands of physical and circumstantial evidence incriminated Mr Skantha.
The defence case relied on the prosecution's key teenage witness being a criminal mastermind and Mr Skantha having the misfortune of all the evidence happening to point to him, he said.
Mr Skantha had a compelling motive for killing Miss Rush, Mr Bates said.
She was willing to go to police and his bosses at the Southern DHB with claims he was touching up minors, supplying them alcohol and offering money for sex.
The final message exchange between the pair - which took place only hours before she was killed - showed that.
"'So you serious?' [Skantha messaged the teen].
"She says, 'best believe I am'," Mr Bates told the jury.
"'I'm doing the world a favour people like you don't deserve to walk freely'."
Those messages demonstrated Miss Rush was willing to come forward with her allegations which would end Mr Skantha's career.
His employment was already on thin ice after he showed up to work while off-duty - and after drinking two beers - and flushed the IV line of a patient.
The jury heard his job was only saved because he had lied about the death of his mother.
"It's not only his job that's at stake, it's his liberty," Mr Bates said in his closing address.
"He's going to be a rooster to a feather duster overnight.
"Amber and her phone had to be silenced as soon as possible. Within 30 minutes of that extra message she is dead and her phone has been taken."
Miss Rush's killer has to have a compelling and immediate reason to risk entering her home and stabbing her to death, he said.
Amber-Rose Rush. Photo: Supplied
While the accused had such a motive, the prosecution's key witness - and the defence's alternative killer - did not.
"He's [the witness] not a compulsive liar. He exaggerates. He makes comments that are unusual from time to time. He's not a person who would viciously kill a friend, a person who's been good to him. And then at the same time set up another very good friend for murder."
Miss Rush's and Mr Skantha's DNA was found mixed in blood taken from his car, multiple witnesses testified to a fire the day after Miss Rush's death in which Mr Skantha burnt his clothes, and his cell data - which could provide clues to his location - was deleted for 2-3 February, Mr Bates said.
He asked the jury to let their common sense guide them.
"Common sense will tell you, you would have to be extremely unlucky not to have killed Amber Rush and to be faced with all this evidence pointing to you."
Defence's case
Defence lawyer Jonathan Eaton said the prosecution's case was built on the testimony of an unreliable witness.
A witness who had form in lying to the police and demonstrated his own concerning behaviour.
In December 2017 the witness was interviewed by the police in regards to sexual offending. He lied throughout that interview denying having any sexual contact with the victim.
"The Crown case cannot succeed, cannot give rise to a guilty verdict unless each and everyone of you are content to believe [the key witness] is a credible and reliable witness.
"If you have doubts about that you must acquit Dr Skantha."
Police took a "blinkered approach" to investigating the matter and never cast a spotlight on the teenager, Mr Eaton said.
That blinkered approach tainted all the evidence and carried into the courtroom.
"As you know in this case without any investigation whatsoever - zero investigation - the police decided [the key witness] wasn't an accomplice," he said.
"That very first interview, those opening lines - having only known [the key witness] for a matter of minutes - Detective Cameron said 'Hey, you are a witness, you are not a suspect."
The prosecution case took three weeks to present to the jury and last Friday the Crown called the last of its 69 witnesses.
Yesterday morning the defence told the court it would not be offering any evidence or calling any witnesses.