Two more people were stabbed to death in London at the weekend.
The stabbings come as the number of killings so far this year approaches 60 in London.
He died later in the evening.
A 34-year-old woman was arrested on suspicion of murder at the scene of the Colindale attack.
Officers attended the location along with London Ambulance Service and paramedics from London's Air Ambulance.
At a house in Brixton a woman in her 30s was killed and...
The victim was rushed to a hospital with wounds considered serious but not life-threatening, according to the Nagaoka Police Station.
The suspect is employed at the same company as the daughter of the victim.
A spokesman added: "Officers are in the process of informing next of kin".
Formal identification and a post-mortem examination are due to take place.
Almost 60 people have been murdered so far in London this year - a lot of them killed with a knife.