No jail, even a child jail, is the answer to knife crime

The problem is still desperately serious. Over the past two years, 89 London teenagers have been charged with murder. But that statistic is a lagging indicator a reflection of the recent past.

What's interesting now is that after a year or so in which three to four London kids died every month, the rate may - just may - be slowing down. No teenager has been killed in the capital since Craig Marshall on 26 September, five-and-a-half weeks ago. There have been only two killings, Craig's included, since the end of August.

It is still too early to draw a firm trend in something as relatively rare and as volatile as teenage murder. We had more than a month's "break" between late March and early May, too, after which there was a renewed spate of horrific attacks.

Craig, the 27th London teen murdered in 2008, set a grim new annual record for the crime, with three months of the year to go. Though about half that time has now passed without further fatalities, we probably won't reach the end of December in the same state.

Yet the Met also last week claimed a 10 per cent annual fall in overall knife crime, where there are enough offences to establish a trend. True, the figures are for all knife offences - not just ones causing injury - and for all ages.

And true, the figures came out the same day as some forces, including the Met, admitted they'd been undercounting violent crime. But if the counting was carried out on the same basis both years, the comparison, if not the actual figures, may still be valid.

If there is indeed a reduction in knife crime, it won't be Boris's doing. He hasn't been around long enough. As I wrote in the summer, when stabbings were at a peak, knife-carrying is one crime that could actually improve of its own accord. It's heavily influenced by peer example, a perverted form of teenage fashion - and fashions change. The Mayor's task today is to push at the behaviour change that may, and I stress may, already be happening.

So I was encouraged by the way Boris's deputy, Kit Malthouse, condemned public "intolerance of young people" and "macho" punishments. We have moved from a society where kids playing in the street were a much-desired barometer of safety to one in which it's grounds for Asbos all round. Children are not little adults. They're what adults make them - and if we get there early enough, and try hard enough, the bad ones can be re-made.

Boris and Malthouse are right to put the emphasis on education, with programmes to stop truanting, support the schooling of kids in care and boost organisations such as the Scouts. But talk of a new child jail for first-time offenders is wrong. However much it might want to be a kind of secure college, it will, like all jails, become a gateway to perdition. It should never be a first resort. Luckily, it's difficult to see magistrates and judges falling in with the plan.

The problem with initiatives is that they have to be eye-catching. But rescuing a child screwed by his upbringing is the work of years, not of a three-month jail sentence. I believe that the Mayor understands this. And if the crisis is indeed abating, it might give him the political room to put into effect.

Bending the bus figures

MY favourite Assembly member, Labour's transport chair Val Shawcross, bravely continues her suicide mission to save the bendy bus, quite without thought to her own political safety.

She claims it will cost "£300,000 per vehicle, per year" to bring in new single and double-deckers — a figure that would be plausible only if Jonathan Ross were driving and Lakshmi Mittal checking tickets. Even this month's issue of the restrained industry trade journal Buses calls it "naive" and "amazingly high".

Representatives of La Shawcross could not, when asked, explain how she had arrived at the amount. It's never a good sign if the only way you can make your case is to appear to make it up.