Murder detectives are investigating whether a fight between armed masked youths on mopeds is linked to the fatal stabbing of a 15-year-old boy.
Aspiring architect Jermaine Goupall was killed in the street in Thornton Heath, south London, less than 100 yards from his home after an evening with friends.
He was ambushed by three men wearing balaclavas, who were armed with knives and a machete, in Green Lane at about 11pm on Tuesday.
Paramedics fought to save him but he was pronounced dead an hour later.
His family said he was a talented mathematician, played badminton and rugby and was an “excellent” swimmer. They have called for youths to “lay down their knives” in the wake of the killing.
On Saturday, Scotland Yard said detectives were investigating whether an altercation in the same area involving masked youths armed with sticks was linked to the killing.
Detective Chief Inspector Tony Lynes, who is leading the investigation, said: “Our investigation has also established that there was an incident in the same area as Jermaine was attacked at around 3pm to 4pm on that Tuesday afternoon. This was an altercation involving a number of teenagers armed with sticks, and some on mopeds, wearing balaclavas.
"One line of enquiry we are exploring is if there is a link between this incident that afternoon and the later altercation that led to Jermaine's death.
"If you were in the area around that time and saw anything, or know who was involved in this fight please call our incident room.
"Jermaine's family are devastated by his loss, my thoughts are with them at this difficult time. Please help us find the people responsible for taking their son from them."
He also urged anyone who witnessed the fatal stabbing of Jermaine to come forward.
DCI Lynes offered reassurance to anyone who was worried about coming forward and said “experience detectives” would deal with the information “sensitively”.
A 16-year-old boy and an 18-year-old woman have been charged with murder and were due to appear at Bromley Magistrates’ Court on Monday.
Anyone with information that may assist the investigation should call the Homicide and Major Crime Command incident room on 020 8721 4868 on via 101.