With plebgate at the forefront of his mind, senior Tory David Davies has called for police officers to be issued with body-worn cameras and recording devices. He sees "a culture of cover-up" in British policing and cites the arrival of research from Rialto in California, which found that a camera attached to a police officer's hat, shoulder, collar or custom-built Oakley sunglasses brought about more than a 50% reduction in the use of force by officers and reduced complaints by 90%. So should body-worn cameras be standard?

Use of body-worn video (BWV) is already widespread in the UK. Devon and Cornwall police were the first to try it, in 2007. In Hampshire, the technology was introduced five years ago, and now it is used by services including Grampian, Gloucestershire and the Met. The College of Policing is engaged in "a scoping exercise" ahead of its own trial. If successful, the deployment of cameras will become systematic and standardised: currently forces can each devise their own rules of use.

So are the cameras needed to monitor the behaviour of the police, or those they interact with? Both, says Barak Ariel, who worked on the Rialto trial and is also working with the Police Executive Programme at the University of Cambridge on research studies with UK forces.

"The focus of the cameras was to reduce the use of force, both justified and unjustified. In terms of civil liberties, everybody is using personal cameras these days: it's just a matter of who is doing the recording," he says. "It's a question of balancing rights with what the police should be doing. If the police should be doing stop and search, at least you have a mechanism there that keeps all parties in check."

"We are seeing the viability of large numbers of equipment," says inspector Steve Goodier of Hampshire police, which spent £250,000 updating its equipment this summer. "We are well beyond the trial – we use it in anger, dare I say, across all our policing areas." His force is working on a research study with Portsmouth University, but his anecdotal evidence already bears out the Rialto findings. Goodier has no complaints about BWV, though he sees it as a means of gathering evidence rather than holding police to account.

A quick stop-and-ask of people milling around London's Kings Cross area showed eight in favour of BWV and two against. None of the 10 feared an impact on their civil liberties. Equal numbers mentioned Mark Duggan as Andrew Mitchell.

Professor Mike Tonge of the University of Cumbria, however, does have one worry about the consequences of BWV for policing. He spent 30 years in the force before turning to academia. "If things are not caught on video, do we still trust the police officer to give that verbal evidence?" he says. "My worry is that people will have an expectation that everything is filmed and the uncorroborated word of a police officer may be a casualty of that."

Plebgate, of course, hangs on the uncorroborated word of an officer, but how differently would the incident have played out if the officers at the Downing Street barrier had been wearing recording devices? After all, cameras tend not to be switched on for impromptu scenes. "If you look at Mr Mitchell he was a little distance away," says Tonge. "The technology at the moment is not always picking up audio from a distance. It might not have captured their words.