By Dominic Casciani
The number of crimes committed by girls has jumped by a quarter over three years, figures show - so is there something to be worried about?
Experts say there is evidence that bullying by girls is turning physical
Ten years ago there was a spate of headlines warning that so-called "girl crime" was on the march - that girls were becoming violent and guilty of anti-social behaviour.
That was before "anti-social behaviour" was a phrase as commonplace as cheap lager in the hands of street corner yobs.
Now, in May 2008, fresh figures on offending show another stark increase - in percentage terms at least - in the number of crimes committed by young girls.
Putting the statistics on girl crime to one side for a moment, the overall impression given by the Youth Justice Board's (YJB) latest figures is of little major change.
As a whole, offences committed by young people fell, although the total still hovers around 300,000.
The number of offences committed by young men also fell slightly.
The YJB figures show the most common juvenile crime is theft, followed by violence - typically minor assaults.
No female Fletch
Historically, men commit more crime than women, but that pattern has been changing very slowly in the UK and comparable nations.
In 1957, men were responsible for 11 offences for every one perpetrated by a woman. today that ratio has narrowed to four-to-one.
Even so, female offenders in the UK are unlikely to be serious, repeat offenders - there just isn't really a female equivalent to Fletch, Ronnie Barker's character in Porridge, wasting his life with yet another stretch inside.
Studies and statistics reveal a complex picture of modern juvenile female crime and it's one that criminologists are yet to see in all its detail.
HAVE YOUR SAY
Send a message that you can not get away with it just because you are a girl
John Smyth, Brighton
According to the YJB's report, girls and young women were responsible for 59,000 offences in 2006-07 - far fewer than the number committed by boys.
However, experts have seen increases in theft, violence and public order offences among girls.
At a local level there is a very mixed picture. Some Youth Offending Teams, the people who try to tackle the problems, say that girl crime - and girl gangs - are an issue. Others say it's more the headline writers' imagination.
Overall, we are not talking about a great deal of crime nationally, but something has been changing.
The problem is nobody is sure what.
Mixed peer groups
In 1998, Dr Ann Hagell co-authored a major study of anti-social behaviour. She says girl crime has to be looked at with a little historic distance from headlines and moral panics.
"These are long-term trends that have been going on for a good 20 years or more," she says.
"The most likely causes are to do with the way people spend their time."
Dr Hagell says that 50 years ago girls and boys simply did not socialise in the same way as they do now, which meant that girls who would be today considered as potential troublemakers were far less likely then to come into contact with boys who provide the temptation.
"Before, we had single-sex peer groups, but now they are more likely to be socialising with boys. In the 1950s they just didn't have the chance to do that.
"You now have a big period in late adolescence with big opportunities to be basically hanging out, and crime can be a consequence."
A great deal of the debate in the criminal justice system focuses on different ways of intervening early enough to prevent juvenile delinquency becoming irreversible criminality.
Professor Sue Bailey, a forensic child psychiatrist based in the north west of England, has studied the causes of aggression and violence among girls who offend.
She says that while there are similarities to boys, there are also differences.
"The typical thing about girls is that the aggression is displayed through relationships, for instance bitching about others. But there have also been small rises over 20 years in actual violence.
"Whereas before they would have been acting as the look-out [for boys], some will now be doing these things themselves."
Professor Bailey says the causes are complex, but evidence shows girls with certain backgrounds need support to avoid slipping into violence and crime.
Extremely temperamental behaviour in little girls may be a warning sign, she says, if attention deficit disorder has not been diagnosed.
Some may share the same formative experiences as boys - alienation, rejection by parents and poor schooling.
But other triggers are specific to being a girl, such as sudden physical changes brought on by early puberty.
These girls might then become the more vicious bullies because they have grown bigger and faster than their peers.
The allure of the dangerous boy can also play a part, and that brings with it other problems such as rape and teenage motherhood.
Crucially, Professor Bailey says, an adolescent mum unable to cope with her child, and particularly one with support from neither family nor the father, runs the risk of raising a baby girl to be even more angry than she was herself.
"Ultimately, we are starting with a low base for girls involved in violence," says Prof Bailey.
"In fairness to the Youth Justice Board, it is looking at ways of addressing these issues.
"The key is to target the high-risk girls."