A man has been arrested after three people were stabbed over six days in north-west London.
Delivery driver Leon Street, 48, was stabbed to death last Monday near the home he shared with his fiancée in Neasden.
Another man, 47, was stabbed 10 minutes earlier near Neasden Lane and the third victim was attacked on Sunday morning.
A 20-year-old man was arrested on suspicion of murder and two counts of GBH with intent on Tuesday.
The two other victims have since been discharged from hospital.
Detectives have an open mind as to any motive for the stabbings, however none of the victims were robbed, the Met said.
Det Ch Insp Tom Williams, said officers were progressing with numerous lines of enquiry but wanted the public with any further information to come forward.
"In particular, I want to hear from anyone who saw a man running or otherwise acting suspiciously in the Neasden Lane North area between 21:00 and 22:00 last Monday or at around 09:50 on Sunday morning," he said.
"I also want to hear from anyone who has seen a man hanging around the area in recent weeks."
A 47-year-old man and a 33-year-old man who were arrested on 11 January have been released without further action.