The death of Mark Duggan, which sparked the August 2011 riots, would have been easier to resolve had the officers been wearing cameras, the Metropolitan Police has said as a major trial of them begins.
The trial, thought to be the largest in the world, will see a total of 500 body-worn cameras distributed to 10 London boroughs. Firearms officers will also be testing the cameras in their training environment with a view to wearing them if the pilot is successful.
The Met was criticised over the death of Duggan, who was shot by its officers. The moments before his death - and whether he was armed - were hotly disputed.
Met Commissioner Sir Bernard Hogan-Howe told BBC Breakfast: "I think as we saw in the recent incident - fairly recent incident - regarding Mark Duggan, there was a great dispute about what Mark Duggan was holding at the time he was shot, and this hopefully would have helped to resolve that."
"If officers are found to regularly fail to switch on their cameras when they should do it will be treated as a disciplinary offence, he added.
He added the cameras would "capture the reality of some of the horrible things we have to deal with from time to time".
Duggan's death intensified the debate over the police's use of body-worn cameras.
The camera trial comes after a jury at the inquest into the 29-year-old's death concluded in January that he had been lawfully killed - a conclusion which prompted outrage from his family and supporters.
None of the officers involved in the incident in Tottenham were wearing body cameras.
Sir Bernard added: "Body-worn video will not only help us fight crime and support victims but help the Met to be more accountable
"Our experience of using cameras already shows that people are more likely to plead guilty when they know we have captured the incident. That speeds up justice, puts offenders behind bars more quickly and protects potential victims.
"Video captures events in a way that can't be represented on paper in the same detail and it has been shown the mere presence of this type of video can often defuse potentially violent situations without the need for force to be used.
"I believe it will also show our officers at their best, dealing with difficult and dangerous situations every day but it will also provide clearer evidence when it's been alleged that we got things wrong. That has to be in both our own and the public's interest."