If the police give up on low-level crime, we all pay a high price | Deborah Orr

Crime reduction remains one of Britain’s recent success stories. Back in 1995, according to the Crime Survey for England and Wales, about 40 in 100 adults reported being victims of crime. By 2007 that figure was down to 24. The latest figures suggest it’s now 15.

Yet over the past three years, even though fewer and fewer people are identifying themselves as victims of crime, the number of crimes recorded by the police has been going up. This year’s figures show a big jump, of 13%. What’s more, the largest rises are in some of the nastiest categories. Knife crime is up by 26%. Sex crimes have increased by nearly 20%. Murder by 8%. The police admit that differences in recording methods account for some of these changes – but the rise in some groups, especially low-incidence serious crime, is a trend that cannot be denied or explained away.

The leap in knife crime is, of course, worrying, not least because there’s a tendency for increased knife crime to encourage more young people to carry knives – for their own defence – which in turn guarantees further escalation. It’s rather like gun crime in the US, except that there’s not a huge, powerful lobby ridiculing the obvious at every turn.

It’s nearly 10 years since my neighbour, 18-year-old Freddy Moody, was stabbed to death outside my home. He was killed in July 2008, and was the 21st teenager to be violently killed in London that year. Nationwide, things have improved so much since those awful times. But these latest police figures make it starkly clear that crime is rising again.

A successful campaign to reduce knife crime followed the death of Freddy and so many others. The message from that campaign is that efforts have to be continuing rather than sporadic. Every knife crime case has to be followed by initiatives to engage, reassure and educate the local community, or fear and bravado will reign.

So much of policing is about signals, indicating what society will and will not tolerate. This week the Metropolitan police said it may stop investigating many lower-level crimes as a result of spending cuts: that means burglaries, thefts, and assaults where there is judged to be little prospect of identifying a suspect. Of course this is financially motivated – the Met, like other forces, is facing heavy funding cuts, and police staffing numbers have fallen to their lowest point for 30 years. But even so, this direction of travel feels wrong on many levels. For it is imperative that victims feel absolutely certain that their reports of crime will be taken seriously, and that they will be supported in reporting such crimes.

Just as important, perhaps, is the notion on the part of those who commit crimes that there is at least a chance of them being traced and caught. Not so long ago, the fashion in policing was for the “broken window” approach – imported from the US, it stipulated that even the most trivial crimes were to be pursued with vigour, in the belief that chasing small crimes prevented a deeper malaise and an escalation of criminality. We have completed a sorry journey from that strategy to this state of non-investigation.

Our relationship with the police is complicated. Back in the mid-1990s, when getting on for half the population had been a victim of crime in the course of a year, the basic problem was that faith in the police was understandably low, because clear-up rates were appalling. Fewer crimes alongside more reported crimes, as is now the case, is actually a sign that belief in the ability of the police to intervene positively is still quite high.

But that can only change for the worse if the Met walks away from its societal responsibilities. And it’s not just the Met. Look to Norfolk, where police chiefs also seem ready to dilute the focus on minor crime and crime prevention, by getting rid of their 150 community support officers. They say they can use the money to provide 81 more police officers, at a time when their budgets are being slashed. But since the support officers were introduced in the first place so that links between the public and the police service could be strengthened, concern about the plan is understandable.

This follows a pattern. In many areas of public service, the idea that early intervention can detect problems when they are minor, and perhaps containable, has been set aside. But this is a false economy, particularly so in respect of crime. There is the cost to victims, who can be highly traumatised even when exposed to minor crime. But more than that, of course, there’s the cost to everyone in a society that feels unprotected. A pattern here, indeed. Cut back in haste, repent at leisure.

• Deborah Orr is a Guardian columnist