The Met said it had almost completed a £10 million year-long project to roll out cameras across the force in a bid to increase public trust in the police.
Today, mounted police officers — one of the last specialist groups to get the devices — were being equipped.
A senior officer today claimed the move had led to greater transparency in stop-and-search encounters, more guilty pleas by suspects and fewer complaints against officers.
The Met revealed figures showing there were 3,515 complaint allegations against officers in the year to October 2017, compared with 4,501 in the previous 12 months — a fall of 22 per cent.
Commander Neil Jerome, who was in charge of the roll-out of cameras, said: “Clearly it is difficult to attribute this reduction entirely to body-worn video but we know it is leading to a reduction in complaints, which is good news.
“These cameras give us quality evidence immediately and allow us to capture a victim’s account with all its emotion and context.”
A final 1,000 officers from the Met’s royalty, specialist and diplomatic protection commands will get the cameras early next year. Police say the delay has been caused by difficulties in installing the technology at sites such as Buckingham Palace.
Mr Jerome said that during the terror attacks at Westminster and London Bridge, body-worn video had been crucial in identifying the perpetrators and establishing there was no continuing threat.
The Met said that since it began rolling out the cameras, officers had recorded more than 1.6 million videos and now submit 4,500 clips to the Crown Prosecution Service each month.
A total of 535,000 videos have also been retained for “evidential or policing purposes”.
Sophie Linden, deputy mayor for policing and crime, said: “Body-worn video is a huge step forward in bringing our capital’s police force into the 21st century.
“From training new recruits to scrutinising stop and search, body-worn video is being used in a range of different ways by our police officers.”
However, Renate Samson, of Big Brother Watch, said: “We keep hearing from police forces that body-worn video is brilliant but we have asked police forces for information to support this and not one could give data to show, for instance, that it is increasing the number of convictions.”