Giovanny Rendon Bedoya was found injured on Hillingdon Street just before 9.20 pm on April 14.
However, he was declared dead shortly after.
Six people were arrested under suspicion of murder and three were rescued pending new investigations.
The other three have been released without further action.
Detective inspector Kate Blackburn said: “On Monday, we recovered several calls from 999, to Hillingdon Street, Se17 reported that a young man had been stabbed and that several people were seen with knives.
“Upon his arrival, the officers found a 21 -year -old man who had suffered serious stab injuries
“It was treated by the London ambulance service before being unfortunately declared dead on the scene.
“Now I can name the victim as Giovanny Rendon Bedoya de Walworth.
“His closest relatives have informed Bone and are currently being supported by specialized officers.
“Our thoughts remain with them at this incredible difficult moment.
“After the incident, we immediately made six judgments. Of the six people arrested, three do not have one more leg and three have rescued awaiting new investigations.
“Now I would like to appeal to the public to obtain information.
“Please, if you saw, listened or has some footage after this incident, then present. Your information can significantly help our detectives with your research.
“We believe there were many people in the area who saw the group, who house the police.
“Were you in the Hillingdon Street area on Monday night? Did you see someone acting suspicious? Did you see someone carrying a knife? If so, contact the police.”
Superintendent Detective Emma Bond, who is acting BCU commander for Lambeth and Southwark Policing, added: “I recognize that this incident has caused a deep group in our communities.
“I want to assure everyone today that we are working 24 hours to find the perpetrators of this attack and take them to justice.
“You can expect to see a greater police presence in the next few days and we have more neighborhood officers in patrol in the surrounding areas this week.
If someone has any concerns, please approach the thesis officers, or their local neighborhood teams, since we are here to help.
“I want to reiterate what DCI Blackburn has said, and urges anyone who has information about this incident to contact us through 101 indicating CAD7392/14 Apr.
“Thank you all for your support and our thoughts and prayers leave the family and friends of the victim involved.”
The investigation is still ongoing.
