Metropolitan Police hope the cameras will add a greater level of transparency to their work. Accused citizens should, in theory, be able to call on these images to prove their innocence. They could play a similar role for the police, helping officers to defend their actions on the street. It's hoped that the new hardware will play a preventative role too, discouraging both sides from acting outside of the law in the first place.

Sir Bernard Hogan-Howe, Metropolitan Police Commissioner, believes the cameras can make the court system more efficient -- if footage of the incident exists, many offenders will plead guilty immediately, rather than hide the truth. "Video captures events in a way that can't be represented on paper in the same detail," Hogan-Howe added. "A picture paints a thousand words, and it has been shown the mere presence of this type of video can often defuse potentially violent situations without the need for force."

The Met says the rollout is the "largest" of its kind in the world. Officers will be kitted out in phases, with an expected completion date of "next summer." It follows years of trials, as well as public consultation and academic evaluation. Similar hardware has been deployed in the US, where police trust has fallen to an arguably greater low. Body cameras, if used fairly and consistently, could help to repair that fragile relationship.