Venod Skantha (32) is on trial before the High Court at Dunedin after allegedly murdering 16-year-old Amber-Rose Rush in the bedroom of her Corstorphine home late on February 2 last year.
The Crown says the defendant's motive was the protection of his medical career, which was in jeopardy because the victim was planning to make sexual allegations to police and the man's Dunedin Hospital bosses.
Skantha was allegedly driven to and from Amber-Rose's house by a teenage boy - the prosecution's key witness with whom he spent the next couple of days before police intervened.
Moving into the third week of trial, the jury heard from two of the teen witness' friends who were with him the night of the killing.
A 23-year-old woman whose name was suppressed said she heard a phone conversation between her friend and Skantha about a social media post by Amber-Rose which was derogatory to the defendant.
"I remember Vinny sounded angry and quite stressed and [my friend] was trying to reassure him . . . [Skantha] was being loud and talking fast'', she said.
Defence counsel Jonathan Eaton QC confirmed with the woman she had never heard his client speak before then.
"I know what the human emotion of anger entails'', she said.
While she said the teenager appeared worried about the social media stoush, Sam Charteris-Cope (22), who was socialising with them, said he seemed unmoved.
The teenager was then allegedly picked up by Skantha and drove him to Amber-Rose's home.
Before he left, friends said he told them if he died he wanted his ashes pressed into a vinyl record.
Shortly after, at 11.54pm, the teen called Mr Charteris-Cope.
"Hey guys, I don't want you to panic but I think I might be an accomplice to murder'', the key witness told them.
The woman said he sounded "upset and confused'' and hung up after saying he had chosen the wrong words.
Skantha and the teen then spent two nights in Balclutha before returning to Dunedin where they met the victim's mother, Lisa-Ann, at a motel.
Detective Constable Amy Stewart - who posed as the woman's friend - told the jury the defendant gave Ms Rush flowers and a card, told her he was "so sorry'' about Amber-Rose's death, and hugged her.
Skantha asked Ms Rush what had happened to Amber-Rose and when she told him, he suggested possible suspects including her step-father, and an ex-boyfriend who had broken Amber-Rose's arm.
She told the court Skantha did not appear upset during the visit, but was "jiggling his leg'' while sitting down talking to Ms Rush.
Police were tailing Skantha at the time of the motel visit, but Det Const Stewart said she was unaware of that at the time.
Yesterday, the court also heard from the family of the key witness.
His father and mother both took the stand, and a statement from his grandmother was read to the court.
All three recounted receiving calls from the teen telling them their lives were in danger, because Skantha had killed Amber-Rose.
The mother said she received a call from her son at 3.25pm on February 4, when he warned her not to go home because "it wouldn't be worth my life''.
She went home anyway and described her son as "distressed and distraught''.
After he left with police, Skantha arrived at the house while the woman was on the phone to her mother-in-law.
He came up the back steps and was heading into the laundry.
Skantha then asked through the window where her son was.
She replied that she had no idea.
"He looked very dazed, very confused'', she said of the accused.
The defendant then left the house.
The trial, before Justice Gerald Nation and a jury of 10 men and two women, will hear from Skantha's Southern District Health Board employers today.
