It’s gratifying, albeit grimly, to see the Metropolitan Police being brought to account over the death of Ian Tomlinson, a blameless newspaper seller whose only fault was to wander in front of some trigger-happy policemen during the G20 protests last week.

In a series of moves that will be depressingly familiar, the Met has gone through a number of versions of its story concerning what interaction its officers had with Tomlinson. I’m not going to go through the sequence of events, as they have been exhaustively covered in the press and wider media.

What is clear is that, even accounting for some likely confusion about what originally happened, the Met has been lying again in an attempt to cover up the over-zealous violence of its officers, and been embarrassingly caught in act of lying once again.

Those who witnessed the squirming that went on during the Jean Charles de Menezes inquiry will have a weary sense of deja vu alongside justified anger that the Met is ultimately responsible for the death of another innocent civilian.

What is heartening about this case, though, is how the explosion in civilian media has brought the police to account and, frankly, will be an increasingly significant threat to police cover-ups in the future.

By all accounts Tomlinson was attacked twice, with several witness accounts corralled by The Guardian and amalgamated into a step-by-step account of the minutes leading up to Tomlinson’s death and the brutality of the police.

The clinching evidence is a video showing a masked, shield-bearing Met police officer shoving Tomlinson hard in the back as he is walking away from a group of policemen. Minutes later he died.

The Guardian’s case is watertight. Having located a dozen witnesses, most of whom took photos showing the sequence of events, as well as a businessman with the key video footage, it has been able to construct a timeline with a previously-unthinkable level of detail.

I’m not immediately aware of such a game-changing development in media in recent years.

Whereas previously press photographers and cameramen from news organisations would be the only chance of capturing something like this, the number of people using media tools will have possibly the most radical effect on police accountability ever.

It’s tragic that this incredible development has been highlighted by the death of Ian Tomlinson, but this event could be a watershed in the way the media, and the public, are able to hold police forces to account.

The Guardian is rightly proud of its scoop and investigative work, but at one point today it had at least four stories that were slight permutations on the same report and the video, in what was an obvious attempt to capitalise on traffic and stuff the website, via url strings and headers, full of keywords.

A distasteful facet of a sad story.

• Image by zongo69 via Creative Commons.