A murder investigation begins after a man in his 30s was found with serious head injuries.
The men stabbed Gregory Catillo Volquez 22 times as they attacked him in a Haringey car park.
David Wynter, 17, died after he was attacked on Engineers Way near Brent Civic Centre.
The attack happened on Tuesday afternoon at the headquarters of Brent Council in north-west London.
Eugeniu Neamtu murdered Gheorghe Trica, three years after completing a sentence for killing another housemate.
Masum Miah, 42, was found fatally wounded inside a car in East Ham in the early hours of Tuesday.
A man has been charged with murder after a woman was stabbed to death in west London.
A woman was pronounced dead at the scene and another, who also suffered stab wounds, remains in hospital.
The British Transport Police says it made the voluntary referral of two officers in the "public interest".
