King, the lone ambulance officer assigned to his ambulance, went to her home and checked her for injuries, which included sore ribs and a bruised head.
The girl told King while the ambulance was still parked at the property that she had been punched but "didn't want to get her [boyfriend] in trouble" and asked King not to tell police of the incident.
She later recalled having reservations about being transported to the Waipukurau Medical Centre under the supervision of a sole male ambulance officer because she "did not trust men".
Crown prosecutor Steve Manning said during his opening address the ambulance then travelled for 10 minutes before stopping on the side of the road near Waipawa, according to GPS tracking evidence. It was there, during a 10-minute window between 3.10pm and 3.20pm, that the teenager was first violated and administered Entonox, a pain-relief gas, the Crown says.
"In particular [King] took advantage of his trusted position as an ambulance officer. Who wouldn't trust a member of St John?" Mr Manning said.
"[He] infused what would have been genuine medical touching with sexual touching."
The teenager said King told her to "keep having the [gas]", despite at this stage feeling little pain from her injuries.
She added that the Entonox acted quickly and that she remembered King pulling her pants down, playing with her breasts and taking videos with his phone as she became disorientated.
She recalled waking inside the ambulance at the front doors of the medical centre with King "touching me in the places he shouldn't be" while he uttered "I could just f*** you".
Mr Manning said the jury would be played CCTV footage of the teenager "literally running from the ambulance" and into the arms of a nearby delivery man as she fled King.
Mr Manning said a police investigation was launched after the incident, resulting in the other three complainants coming forward, all of whom had called 111 asking for medical assistance, including a woman who was terminally ill and had since died.
King's lawyer, Bill Calver, said the defence's argument was that the scenarios put forward by the complainants simply did not happen and that King had "performed his duty professionally, competently but, above all, lawfully".
The Crown also says King deleted the intimate videos of the teenage girl on his cell phone, however the former ambulance officer denies the claim.
Mr Manning told the jury the Crown had "digital footprint" evidence showing King, in fact, did delete the videos as the teen ran from the ambulance.
The remaining complainants are expected to give evidence during the trial, which Judge Geoff Rea indicated would run until next week.