Jodie Chesney was stabbed to death after her killer targeted “the wrong people”, according to the alleged getaway driver.
The 17-year-old girl scout was attacked as she relaxed with friends in a park in Harold Hill, east London on 1 March.
Manuel Petrovic, 20, is one of four youths on trial at the Old Bailey jointly accused over Jodie’s death.
While on remand over the killing, he protested his innocence, claiming he was only asked to drive to Harold Hill and not told why.
During a secretly recorded prison visit by two female friends on 24 May, he said: “I’m going to say I’m a drug dealer, I broke the law with my driving and s***.
“I’m not into murder. I ain’t going to go guilty for something I have not done. I’m no murderer.”
Petrovic allegedly said to a friend during a second visit on 3 August that Jodie was stabbed after his co-defendant Svenson Ong-a-Kwie was “cheffed”.
According to a transcript of the conversation read out in court, Petrovic said: “They went to bang out on their ops and banged out the wrong people.”
When asked how he knew that, he replied: “Uh? Because I know that… It was to do with Svenson’s op – they cheffed him up a couple of month or something, a couple of months before.
“Someone give him the drop, he went to ride out and rid out on the wrong people in the park and they thought it was them because they chill in that area.
“That’s why she got it from behind.”
Asked where the tip-off came from, Petrovic replied: “They got their drop their self bruv. Because they were in a cab in Harold Hill when they text me saying ‘ring me, ring me asap, need to come and see you asap’.”
His recorded conversations in prison also hear him talk of hoping to “bust the case”.
Petrovic’s friend told him he should “take this opportunity” if he got off the charge and take a “nine to five job”.
He denies murder along with Ong-a-Kwie and two youths aged 16 and 17, from east London.
Jurors were told of an incident before Jodie’s death in which Ong-a-Kwie was found with a makeshift bandage around his left thigh.
The defendant was said to have been vague about it, saying: “Basically, this is what happened. They pulled up here in a car, jumped out and stabbed me in the leg.”
The court heard Petrovic had convictions dating back to 2013 including for possession of cannabis and handling stolen goods.
Ong-a-Kwie had pleaded guilty to possession of class A and B drugs when he was 16 years old.
He also had a conviction for the supply of cocaine and having stolen goods, jurors were told.
According to agreed facts read to court, the 17-year-old defendant had been involved in an incident in a shop when he was 14 in which a member of staff was attacked with a screwdriver.
The youth went on to plead guilty to assault occasioning actual bodily harm and possessing a pointed article.
The trial was adjourned until Friday when the defence case is due to start.