Jodie Chesney was an innocent girl whose promising young life was cut short in an act of “casual violence”, police have said.
The 17-year-old Girl Scout was laughing with friends in a London park when two drug dealers emerged from the darkness and stabbed her without warning.
Her distraught boyfriend described how he did not initially realise what had happened in the completely silent attack on 1 March, before Jodie started screaming.
It was only then that her friends noticed blood coming through the back of her coat, from what would later be discovered as an 18cm stab wound.
Jodie died in her boyfriend’s arms, as her two attackers fled the Harold Hill park and into a getaway car.
Her father, Peter Chesney, was celebrating his birthday with friends when police officers arrived to tell him his daughter had been killed.
Svenson Ong-a-Kwie, 19, and Arron Isaacs, 17, have been jailed for murder.
Both had denied being involved in Jodie’s death, with each claiming the other man had stabbed Jodie and was lying.
Sentencing them on Monday, Judge Wendy Joseph QC found that on the available evidence Ong-a-Kwie had wielded the knife, with Isaacs as a "willing, enthusiastic supporter".
"I am satisfied on the evidence that both defendants were prepared to attack their ‘ops’ whenever and wherever the opportunity presented itself," she added.
"I am satisfied that at the moment the knife was driven into and through Jodie, the stabber could have intended nothing but death."
The judge said the killing resulted from a "tit-for-tat" vendetta of escalating violence, and there had been "no true explanation" from the killers over why Jodie was the victim.
Police said the pair had gone into the park “purposefully to stab somebody and they didn’t care who it was”.
Detective Chief Inspector Dave Whellams, of the Metropolitan Police, said officers still do not know why Jodie was targeted.
He said Ong-a-Kwie, a prominent local drug dealer, had “got the hump” with another person dealing on his turf and was seeking retribution.
“He went in the park with intent to cause harm to somebody,” DCI Whellams said. “Quite why it was Jodie we don’t really know.”
The popular teenager was studying psychology, sociology and photography at Havering Sixth Form College and her friends, family and dog Woody “meant the world” to her, loved ones said.
Jodie, a keen classical pianist and photographer, had achieved the Duke of Edinburgh bronze and silver awards and was just a few weeks away from completing her gold.
She was also an active Scout member and “touched the lives of many other young people” through her volunteer work.
Police confirmed that Jodie and her friends were smoking cannabis at the time of the stabbing, but said the group were “innocent”.
Earlier that day, one of her group had unsuccessfully tried to buy £20 of “Pineapple Express” cannabis from Ong-a-Kwie but turned to another local dealer instead.
But Judge Joseph said she "entirely rejected" suggestions that the purchase sparked the stabbing, adding: “The reasons underlying this killing are far more sinister and dangerous than that.”
Another investigator, Det Insp Perry Benton, said: “Jodie was innocent in all of this, regardless of views on whether you can take recreational drugs or not.
“Jodie was innocent and the group in the park were innocent. If they bought cannabis off one person or another there was never a justification for what they did to her.
“They destroyed her family’s life forever, her friends are struggling to cope because of what happened. Jodie and her friends were innocent and didn’t deserve any of this.”
The murder happened after a string of “tit-for-tat” attacks where Ong-a-Kwie had previously been stabbed, and he and Isaacs had launched an unprovoked knife attack on a rival over a girl.
Prosecutor Crispin Aylett QC had told jurors they took a “casual approach to violence” in a world where knife crime was “routine”.
There was speculation that one of the pair’s enemies may have been in the park on the night of Jodie’s murder, but two boys seen on a bench have never been identified or come forward to police.
Investigators dismissed suggestions that the killers had only entered the area for a routine drug deal, questioning why Ong-a-Kwie asked for a lift from his friend Manuel.
CCTV captured the shadowy figures of Ong-a-Kwie and Isaacs disappearing into the park before the sounds of Jodie screaming could be heard.
Petrovic, a 20-year-old drug dealer, and a 16-year-old boy stayed in the car during the attack and were acquitted of murder on Thursday.
Police said Ong-a-Kwie spent his earnings on a large trainer collection, while Petrovic had money “stashed everywhere”.
The friends were on the “same level” of a drug dealing network, controlling local patches and running multiple phone lines to conduct deals while using children as runners.
“They were drug dealers, it was just business to them, they don’t care about the lives they are ruining,” Det Insp Benton said.
“Only the four people in that car know why they went there.”
With the attack happening in darkness and out of the view of CCTV cameras, police said their investigation stalled before a member of the public reported seeing two people running out of the park into a suspicious black Vauxhall Corsa with its lights off.
The vehicle was discovered abandoned, with investigations showing it had been bought by Petrovic and had Ong-a-Kwie’s fingerprints on the bonnet – leading to the four defendants being charged.
Det Ch Insp Whellams said Jodie “could have been anybody’s daughter”.
“She was a very nice girl, she had a small circle of friends, she did well at school, worked in the community, she was in the Scouts, she had been up to Downing Street,” he added.
“She was just an ordinary girl and that’s the tragedy. She was an ordinary girl going about her ordinary business.”
Her father has set up a charity, the Jodie Chesney Foundation, aimed at taking action to steer young people away from knife crime.