A 15-year-old boy has been arrested on suspicion of murder after stabbing a man in front of shoppers in south London.
The teenager was also arrested on suspicion of possessing an offensive weapon. He remains in detention.
Keelen Morris Wong, 22, was killed on busy Coldharbour Lane in Brixton shortly before 5pm on Tuesday.
Police and the London Ambulance Service attended, but Wong was pronounced dead at the scene.
His next of kin are aware and are being supported by specially trained officers, the Metropolitan Police said.
A 23-year-old man, arrested on Tuesday for murder and taken to hospital for treatment, has now been released but remains in police custody.
DI Kevin Martin said police were working to establish a motive for the stabbing.
“This horrific attack took place in broad daylight, in front of people simply going about their business,” he said. “I do not underestimate the impact such a horrific incident will have had on anyone who saw it. We have heard from a number of people, but I am asking anyone who witnessed it to speak to us, in complete confidentiality, about what they saw.
“An arrest has been made and we are making significant progress but we can never have too much information. Our work to establish a pattern is ongoing. Any information, no matter how small, can facilitate the investigation and hold those responsible to account.
“I am also fully aware that a number of videos are circulating following the incident, including those from the crime scene. I know these videos cause immense distress to the victim’s loved ones, and I ask people to respect them by not broadcasting these distressing images.