The 16-year-old was allegedly stabbed to death in the bedroom of her Corstorphine home on February 2 last year by Venod Skantha (32).
He is on trial before the High Court at Dunedin charged with murder and four counts of threatening to kill.
The Crown case is that the catalyst for the violent attack came just minutes before Amber-Rose's death, when she threatened to go to Skantha's Dunedin Hospital bosses and the police with allegations of sexual offending.
The defendant was on a final warning in his job at the time and the victim's claims would have likely ended his medical career, prosecutors said.
ESR forensic scientists spent Thursday detailing areas where blood was found at various scenes and how samples were collected.
A teenage witness previously told the court how he drove the defendant to and from Amber-Rose's house, to Blackhead where her phone was allegedly dumped, back to the defendant's Fairfield home to clean the car and then on to his ex-girlfriend's home in Balclutha, where they spent the next two nights.
Yesterday, another ESR scientist, Timothy Power, explained the analysis of the samples and the statistical likelihood of the DNA profiles.
On the window of Skantha's silver BMW, were six small blood droplets and investigators found other marks on the bottom of his grey suede shoe.
Mr Power said the blood was 800,000million times more likely to be from Amber-Rose than another random member of the country's population.
A transfer blood stain on the car's passenger door came back with a mix of two or more people's DNA.
Mr Power's analysis showed it was ninemillion times more likely to be from Skantha and one other than two random people; and 40million times more likely to belong to Amber-Rose and one other.
That, too, was an extremely high likelihood of accuracy.
Defence counsel Jonathan Eaton QC clarified the DNA match did not mean there was specifically blood in the sample.
Under cross-examination, Mr Power also confirmed that there was no way of telling when someone's DNA was deposited on a surface.
Mr Eaton intensely questioned his client's teenage friend when he gave evidence earlier this week.
He suggested the witness had deliberately put the blood on Skantha's shoes to portray him as the killer.
Similarly, Mr Eaton said the blood in the car must have been planted to frame the doctor.
"You must've had, whether on Amber's licence or something else, some of her blood. You had access to that and rubbed or flicked it around the car," he said.
The teenager denied doing so.
The trial continues.
The trial this week
Monday
- Key witness says Skantha admitted killing Amber-Rose
- He tells police he deliberately left evidence for them to find
- Teenager tells the court Skantha burned his bloody clothes
Tuesday
- Skantha’s teen friend denies being obsessed with Amber-Rose
- Star witness admits he went to media trying to sell his story
- Teenager acknowledges lying about Skantha threatening him with a knife
Wednesday
- Key witness is revealed to be a sex offender who previously lied to police
- He denies calling friends on the night of the murder to create an alibi
- Teen says Skantha acted out the stabbing of Amber-Rose on him
Thursday
- Amber-Rose’s blood found on Skantha’s shoes and passenger side of his car
- No blood in the door’s side pocket where knife was allegedly stored
- No forensic evidence to tie Skantha to the murder inside victim’s house