A man was found stabbed in a south London street on Sunday morning.
The emergency services were called to Upper Green East in Mitcham at 3.29am. Paramedics tried to save the man, who was in his 20s, but he was declared dead at the scene.
The Metropolitan police said a 44-year-old man was arrested at the scene and remained in custody.
The Met has been under pressure over a rise in homicides this year compared to last and had been providing a public count on how many killings it was investigating. It no longer does so.
The number in London so far this year is believed to be over 60. The Met commissioner, Cressida Dick, has set up a taskforce to try to stem the violence.
The Met said officers were working to establish the identity of the man who died in Mitcham and to trace his next of kin.
The force said: “A postmortem examination will be arranged in due course. We await formal identification. An investigation has been launched by detectives from the homicide and major crime command, led by DCI Simon Harding.
“A 44-year-old man was arrested at the scene on suspicion of murder. He has been taken to a south London police station where he remains in custody.”
In 2017 there were there were 116 murders, excluding the killings in three terrorist attacks that struck the capital. The total for 2018 is expected to exceed that.
The London mayor, Sadiq Khan, said: “The homicide team is investigating and they will do everything they can to bring the perpetrator to justice. My thoughts are with the victim’s family.”
He said he had contacted the Met, the local MP and local council leader about the incident.
