An elite group of police officers have the job of identifying each suspect captured on CCTV.
Known as super-recognisers, these policemen have the ability to match faces on camera to those stored in their photographic memory.
This exceptional ability has helped prosecute hundreds of people who took part in last summer's troubles.
More top news
Bees Number One is 'best in the league."
A union has said it is worried plans for Wandsworth and Richmond councils to merge may lead to job losses.
A computer disk contained a secret file on the fatal shooting of Mark Duggan by police has been lost.