A 16-year-old boy has died two weeks after being stabbed in Brixton.
He was rushed to hospital where he later died.
The date of death will be recorded by doctors as 20 April.
The Met’s investigation into the stabbing is now a murder investigation.
A 16-year-old boy was arrested on April 15 and a 17-year-old boy was arrested on April 20.
Both have been bailed until mid-May.
Detective Chief Inspector Sal Minhas, from the Specialist Crime Command, said: “A 16-year-old boy has lost his life and his family deserve answers to their questions about what happened to him.
“I want to reassure Rommel’s family that we are committed to bringing the person or people responsible to justice.
“Thank you to everyone who has spoken to police already about this incident. If you have not already contacted us, it is now even more vital that you do so without delay. Please let my team be the judge of what is important as you may have information that will be key to our investigation.”
Detective Superintendent Neerav Patel of the Met’s Central South BCU said: “The Met is making significant progress in reducing violence in London, but tragedies like this senseless murder remind us all that there is much more to do. Local people will have seen additional officers in the area in recent weeks.
“The thoughts of my colleagues and I are with Rommel’s family and particularly his grieving mother. Met officers will be available to support her for so long as we are needed.”
Rommel’s family have been informed and are being supported by specially trained officers.
Anyone with information is asked to call 101 quoting CAD 6036/04Apr. To remain anonymous contact Crimestoppers on 0800 555 111.
Any young people who have information about violence or knife crime can visit Fearless where they can pass on information anonymously – your I.P address will not be traced. Fearless is part of the Crimestoppers charity, and is also independent of the police.