I’ve talked before about how sometimes a prism forms over a story, so that after a while only one side gets heard. It happens most often to politicians, usually those in power, most intensely when a situation develops with all the ingredients to show them in a bad light. But enough of Damian McBride.

It seems to be happening to the police as well. Anyone with anything bad to say about their handling of the G20 Summit – or, even better, with mobile phone footage to show the badness – will find a ready and willing media and political audience. But any balance in the coverage seems to be being lost.

It is true that the vast bulk of protesters were peaceful. It is also right that there should be an inquiry into the treatment of Ian Tomlinson, and into allegations of violence by police against protesters. It is right that Parliamentary committees are taking an interest in broader issues of public order policing.

But it is also fair to point out the scale of the challenge the police faced on the day, and the fact that most did a difficult job well. 

You sometimes hear civil liberty campaigners complaining that we live in a police state. The fallout from the Summit suggests strongly otherwise. The police, it seems to me, are the ones facing the most intense questioning and under the greatest pressure, far more than those who, also surrounded by people taking pictures on phones and camcorders, were committing acts of criminal damage by smashing in the windows of a bank. If the prism were in a different place, people would be asking what was happening to the investigations into that.

Back to the comparisons with politicians. There are bad ones amid the good. It does not make them all bad. And if we all end up thinking that all politicians are terrible people, all cops are bent or violent, all social workers are useless (more of that around today I see), all teachers politically correct, all businessmen only interested in getting rich, and most journalists thinking the only story worth writing is one which shows one or all of the above in a terrible light, we risk painting a far more negative picture of our society than truly it deserves.

There has to be some relationship of trust between police and public. Of course the police, every single one of them, has to help in that. But the public has a role too. In recognising the breadth of challenges they face. In supporting them in their basic aim of preventing and dealing with crime. In recognising too – not least in the area of race relations – that where there have been problems, they have made real efforts to address them.

It is not very fashionable to say any of that at the moment, because of where the prism rests. But I was struck, and in part moved to write this blog, by a letter in The Guardian today which ends ‘On 18 April you ran a front-page article and photograph about the death of Ian Tomlinson and then inside there was a double-page spread, again with photographs. In contrast, the sad death of PC Gary Toms, who was injured on 11 April in the course of his duties, merited only a 7in column on Page 10. This shows the other side of policing and, in the interests of balance, more could be made of this. An emphasis on the risks police officers take and the fear a lot of them must feel would perhaps partly explain, although certainly not excuse, the outrageous behaviour of some of them at the G20 demonstration.’

Morale in the police is unlikely to be terribly high as a result of the G20 fallout. But is worth remembering that the prism can change, albeit slowly. Two pages back from the letter, Jackie Ashley is singing the praises of Peter Mandelson. That really was a surprise.