Inside the Metropolitan Police’s elite firearms unit
20 January 2014 Last updated at 18:28 GMT
The Metropolitan Police says it was wrong not to formally review the "hard stop" tactic six years before it was used in the Mark Duggan shooting.
The Independent Police Complaints Commission recommended a review in 2005, calling such stops "high-risk".
The force says it is "constantly looking at the tactic".
The 'hard stop' tactic involves armed officers in police vehicles boxing in a suspect's car and confronting them.
BBC Panorama has gained unique access to the firearms unit responsible for killing Mark Duggan and speaks exclusively to serving officers within the unit.
Alistair Jackson reports.
Panorama: Shooting to Kill? BBC One, Monday 20 January at 20:30 GMT and then available in the UK on the BBC iPlayer.