A teenage girl was stabbed to death because she had been “caught up in a quarrel between drug dealers”, a court has heard.
Jodie Chesney, a 17-year-old Girl Scout, was killed while spending time with friends in an east London park on 1 March.
London's Old Bailey heard that the group had been playing music and smoking cannabis, when her boyfriend noticed two people moving silently towards them in the dark.
Eddie Coyle saw the taller of the pair swing his right arm at Jodie's back, a jury was told at the start of a trial of four suspects, all of whom deny murder.
Jodie screamed and the two figures disappeared, as her friends discovered she was bleeding heavily from a deep knife wound.
Mr Coyle, 18, caught Jodie as she fell and eased her to the ground, crying and screaming for her to stay awake as he held her hand, the court heard.
A local resident heard the screams and came to help as Jodie's friends became “hysterical”, jurors were told.
By the time an ambulance arrived, she showed no signs of life and was pronounced dead on the forecourt of a petrol station.
Prosecutor Crispin Aylett QC told jurors that none of Jodie's friends had any idea who was responsible for the “terrible and cowardly” attack.
However, police received a “breakthrough” when a witness reported two males getting into a stationary black Vauxhall Corsa.
But for the “chance sighting” Jodie's murder might have gone unsolved, Mr Aylett said.
A couple of hours after the killing, a black Corsa registered to defendant Manuel Petrovic was found abandoned about two miles away from the park where she was stabbed in Harold Hill, he said.
Following his arrest, Mr Petrovic admitted driving to the area with a friend and two others who had gone into the park to collect money and drugs.
He denied knowing the pair were armed beforehand, the court heard.
Investigators identified Mr Petrovic's friend and the two others through CCTV footage and mobile phone data, jurors heard.
Mr Petrovic, 20, Svenson Ong-a-kwie, 19, were charged with Jodie's murder, along with two boys, aged 16 and 17, who cannot be named for legal reasons.
Mr Aylett said Jodie was a “beautiful, well liked, fun” young woman who had nothing to do with drug dealing and was unlikely to have been the intended target.
“The drug-dealing world is one of turf wars, rivalries and pathetic claims for 'respect',” he told the court. "And when drug dealers fall out, they do not take their problems to the police. Instead, they take matters into their own hands, prepared to use serious violence in order to prove whatever point it is that they wish to make.
"The prosecution allege that all four defendants had gone together in Mr Petrovic's car to Harold Hill in order to mete out violence - and not as Mr Petrovic has claimed, to collect money and drugs.
"If the prosecution are right in saying that Jodie was an entirely blameless individual who got caught up in some quarrel between drug dealers, then her murder was the terrible but predictable consequence of an all-too casual approach to the carrying - and using - of knives."
At the time of her death, Jodie was living with her father Peter, step mother Joanne and older sister Lucy in Dagenham.
The Havering Sixth Form College student had been studying three A-levels and was weeks away from completing her Duke of Edinburgh gold award.
Jodie's family appeared tearful in court as they listened to details of her death.
The defendants, all allegedly involved in drug dealing, deny murder.
The trial continues.
Additional reporting by PA