A 48-year-old man has died after being stabbed on Kilburn High Road on Monday (August 1).
He was taken by the LAS to a north London hospital where he died from his injuries at 8.15pm.
A 21-year-old man was arrested at the scene by police and he is currently in custody at a north London police station.
The next of kin of the 48-year-old have been informed, while a formal identification process is still to be carried out.
Detectives from the Homicide and Major Crime Command have been informed, while a post mortem will also be held in due course.
An incident room has been opened under Detective Chief Inspector Graeme Gwyn, HMCC and anyone with information are asked to call police on 020 8721 4622, or to remain anonymous, call Crimestoppers on 0800 555 111.