A police marksman has been removed from firearm duties after a man was shot dead during a "pre-planned" operation.
The body and the car have been removed from the scene
The Metropolitan policeman was among 25 taking part in the operation in Hale Lane, Edgware, at 2000 BST on Saturday.
After a car was stopped, police fired "a number of shots" and a passenger, thought to be in his 20s, was killed, said independent police investigators.
Two other people in the car were arrested on firearms offences and three weapons were recovered.
Police said the dead man had been seen holding a firearm.
A Scotland Yard spokeswoman said of the moved officer: "He has been removed from arms duties and moved to another role."
An investigation by the Independent Police Complaints Commission (IPCC) began soon after the fatal shooting.
In a statement, the IPCC said: "Police fired a number of shots and the man was hit when in the vehicle.
"The man was given first aid on the pavement but pronounced dead at the scene.
"Two other occupants of the car were arrested on suspicion of possession of a firearm and are in police custody.
The victim's body was taken away in a private ambulance
"Three firearms were recovered from the vehicle and will be the subject of urgent forensic examination."
The IPCC described the operation as "pre-planned by the Metropolitan Police's Specialist Crime Directorate and SO19", which is a specialist firearms unit.
The identity of the victim has not been revealed while his relatives are informed.
Ian Bynoe, IPCC Commissioner, said: "My condolences go out to the family of the man who has died.
"The IPCC will investigate all the circumstances leading to the use of armed officers for this operation together with the justification for shots to be fired.
"The IPCC will ensure that a thorough but timely investigation is carried out to reassure the man's family, the officers involved in the operation and the public."
Eyewitness Chris Webber recalled hearing "rapid fire" before seeing a body being pulled out of the car and attempts made to resuscitate the man.
"The first couple of shots were single shots which sounded like a pistol. The rest of them did sound like machine gun fire," Mr Webber said.
The scene of the shooting was sealed off on Sunday and obscured with large plastic groundsheets. The body and the car were removed from the scene.