A man was stabbed to death as people gathered for a vigil to remember another recent knife attack victim.
Police were called at 9.10pm on Tuesday to reports of three men fighting in Alpha Road, Croydon, south London.
A man who had been stabbed was pronounced dead at the scene, and detectives are confident the victim is 23-year-old Reece Young.
The Metropolitan Police said his family have been informed and are being supported by specialist officers.
Two men had left the scene in a vehicle before police arrived, and later presented themselves at a south London hospital with stab wounds that are believed to have been sustained in the same incident.
The Met said officers went to the hospital and arrested both men on suspicion of murder.
The first man, aged 33, remains in hospital where he is being treated for non-life threatening injuries.
Assaulted police officers
After his arrest, the second man, believed to be in his 30s, assaulted police officers and NHS staff before forcing his way out of the hospital, according to the Met.
An urgent search was carried out and he was returned to custody on Wednesday evening.
Detective Chief Inspector Richard Vandenbergh, who is leading the investigation, said: “We believe this incident was witnessed by a number of people.
“They had gathered for a small vigil in remembrance of another recent fatal stabbing victim when an altercation began.
“Some of those people have already spoken to police, but I believe there are others who captured images and video of what happened. I need those people to contact us immediately.
“The information they have could prove vital in establishing the chain of events that has led to a young man losing his life.”
Anyone with information is asked to call police on 101 or tweet @MetCC quoting CAD 7449/30MAR.