Teenager Mahamed Barre has handed himself in to police following an earlier appeal from detectives investigating the murder of Jamil Palmer in Hanworth.
Police requested that the 17-year-old present himself at a police station this morning (May 21) and he surrendered himself this afternoon.
Mr Barre is currently in custody.
It is believed Mr Barre had an altercation with Mr Palmer on the day of the attack, May 6, and suffered a head injury which he may require medical treatment for.
Mr Palmer was stabbed to death at Crane Park, near Evans Grove, in Hanworth, at about 3.30pm. He died of a stab wound.
Police are offering a £15,000 reward over the murder of Mr Palmer and continue to seek information which will lead to prosecution of the person or people responsible for his death.
Four teenagers, aged 15 and 16, have been previously charged with Mr Palmer's murder.
Anyone with information is asked to contact the incident room on 020 8785 8099 or call Crimestoppers anonymously on 0800 555 111.
