Monday morning and PC Bill Oddy is looking around the Dell - a skatepark-cum-wasteland near Carterton community college in north Oxfordshire. It’s a haunt for truants, he says - a dumping ground for stolen property and the last resting place of the odd burnt-out car, but it looks empty this morning, apart from a few flattened crisp packets in the long grass.

PC Oddy pokes around under the half-pipe skating ramp and soon finds a homemade hubble-bubble, improvised from silver foil, half a plastic bottle and a bucket of water. He kicks away the lollipop wrappers, looking for syringes, then treads down a nettle-filled bank and returns holding a single, white trainer. This being Oxfordshire, he also picks up a ticket for a performance of Romeo and Juliet.

PC Oddy is an unusual kind of policeman. His opening gambit is that he’s not a good driver. “You know that when your three-year-old son tells you to slow down,” he says. He keeps his shoe brushes under his car seat and is prone to losing his keys. More unusually, he is based not in the local police station but in two nearby comprehensives. He’s barely out of his small, unmarked vehicle in the car park at Carterton school before boys - they’re all boys - are crowding round him, clamouring to know when they will get their confiscated lad magazines and ball-bearing guns back. “Did you hear what happened yesterday?” asks one, in what is clearly an ongoing story. “I’ve been told that if I say anything to him I’ll get arrested.”

In a blaze of publicity, the south London borough of Southwark will, this autumn, station police officers in 11 of its secondary schools. One, PC Hayley Nunns, has just started her second term at Archbishop Michael Ramsey school. Further north, in Hackney, officials are consulting over the idea. In the United States, a police presence in schools has been a fact of life for decades. But can the two cultures co-exist in the United Kingdom?

In north Oxfordshire, the experiment between the police and schools has been going on for four years. Bill Oddy has been based in the 700-pupil Carterton community college and nearby Burford school, a 1,050-pupil, 11-18 rural comprehensive, for the past two years. His primary role, he says, is to stop young people slipping into crime. “Most of my work is based around risk factors,” he says. “The police service in general doesn’t do enough prevention-type work, particularly with young people. They’re the biggest offending group and the biggest victim group.”

The risk factors for criminality are well documented, and many of them aggregate around life at school. They include criminal behaviour by children or their families, truancy, domestic violence and poor academic achievement. “If any of these are brought to my attention, I will talk to the school about it,” says PC Oddy. His role is to get involved with children who appear to be going off the rails, talking to them, sometimes visiting them at home, mentoring some, reprimanding others.

The real frustration, he says, is that young people have to be convicted of an offence before they can get the help they need. In outreach work in primary schools and through his knowledge of the community, he often spots children heading for problems in Year 6. Then he encounters them again in Year 11, much further down the line.

Although north Oxfordshire is a rural area - low-key by inner-city standards - crime and disaffection are no strangers here. Carterton is a small town serving the Brize Norton RAF base, with a transient service population, some drug abuse and a degree of social dislocation. PC Oddy’s next task is to inform staff at Carterton of a domestic violence incident over the weekend, involving a pupil. “That kind of thing can explain a pupil absence or behaviour issue,” he says. En route to the office, two Year 8 boys stop PC Oddy, faces grave. A man in a white Nissan with a BMX bike in the back “wheel-burned” past them on the road, they say. They think the bike was stolen from the school. They hazard a registration number and a description of the driver, although one says, regretfully, that there were no identifying features. PC Oddy gets out his notebook. “Thanks guys.”

PC Oddy understands, he says, that some teachers may see a police presence in schools as “oppressive, or a bit over the top”. Some staff have reacted negatively to his wearing what the police call “appointments” (“quick-cuff” handcuffs, baton and CS gas canister) as well as his uniform in school. His predecessor worked in plain clothes. It is difficult, he acknowledges, for one kind of organisation and culture to take advice from another. He has taken a softly-softly approach. “I arrived saying, ‘I’d like to be part of your school in the same way an education social worker is, or a school nurse.’”

He asked for a pigeonhole, briefed staff on why he was there and publicised his contact details. He still goes on patrol in the town twice a week with police colleagues. Pupils, like the local people, call him Bill. Eighty per cent of his work is with boys: one, with a drug-dealing sibling, a violent step-parent and other issues at home, is desperate to talk to him today. “He needs to offload a lot of his anger and a lot of his problems,” says Bill Oddy.

Both headteachers sing his praises. “It’s a return to old-fashioned concepts of community policing,” says Alan Klee, of Carterton. “Often, the youngsters who have difficulties in school also have difficulties in the community. When you have someone who knows them in both contexts, they can be very pro-active. He’s helped us enormously with heading off potential problems and steering youngsters in the right direction.”

Jan Campbell, head of Year 9 at Burford, is keen too. “As far as I’m concerned, Bill’s going to do a lot of preventive work with the young people who are least academically able and most at risk of going off the tracks.” She ropes him in to take a group of off-message Year 10s to a Little Chef for lunch. “Basically, these kids want someone to like them,” she says, as he sits at the other end of the table giving every impression of doing just that.

PC Oddy says staff at the two schools have been supportive. “But,” he says, “I still feel at times that I’m walking a tightrope. I’m a visitor, a guest in the school. I wouldn’t do anything unless the head wanted me to.” Making arrests, the point at which push comes to shove in terms of the culture clash, is a last resort; he says he has arrested only around a dozen pupils at the two schools in the past two years, “mostly as a result of incidents in the community”. Only one arrest has been made on school premises and that was when a pupil assaulted the headteacher. Arrests, he says, can be seen as constructive. “In the main, if I do have to deal with somebody, it can be quite positive for them. It’s not the God-awful experience most people think it is.”

Schools officers, viewed by some police officers as “teachers in uniform”, have been a feature of secondary education for years. Typically, they go from school to school lecturing on drugs education, citizenship and related issues. But basing police officers in schools is fundamentally different. “It’s the logic of treating the school as a community,” says Thames Valley police spokesman David Campbell. “A village of four or five thousand people would have its own police officer.” Schools, with pupils, staff, parents and neighbours, constitute a similar proposition, he argues.

But the demands of the police force and the needs of a school create a tension. The notion that schools should be safe havens for children - and possibly then become a safe haven for crime - is thrown into relief by the presence of police officers in schools. The police are keen that officers in schools gather information that can help reduce crime in the surrounding community - for police, as for teachers, statistics are all-important in the current climate. Bill Oddy, though, has come to believe bringing information into schools is more important than relaying it out. “I’ve often felt responsible for giving schools information I believe they should know.”

It is an uncomfortable fact that almost all offenders have been pupils in schools, many of them recently. Of the 100,000 most persistent offenders in England and Wales, one in two is under 21 and almost three out of four started offending between 13 and 15, according to Home Office research. More than one in three has been in care as a child and one in two lacks any qualifications. Almost half have been excluded from school. A police presence in schools raises questions about how to work with young criminals, and their victims.

In Southwark, police officers are being put into schools with a direct crime prevention remit. “It’s a response to police research finding that young people feel they’re not protected as well as they could be,” says a spokesman for the Metropolitan police. “We were aware of children being victimised and feeling vulnerable and were keen to address it.”

But in areas of deep social deprivation, where relations between police and young people in general - and police and young black people in particular - have been historically bad, the issues can be explosive. One police constable, based for a year in a north London comprehensive, found the differences between education and police cultures almost irreconcilable.

PC Smith (not his real name) had a long-standing interest in working constructively with young people and went in with high hopes for the venture. “School is where the opportunity is to do something with the kids every day,” he says. “They need the contact. Things don’t happen once a week, they happen every day.”

But, once in school, this officer was appalled by the level of pupil-on-pupil violence. He found kids carrying knives, dealing, demanding money with menaces and was dismayed by his own isolation. “I’m not a teacher. I’m not a pupil. I’m a police officer. People were polite and kind to me but you just feel totally lost. There’s no one to share anything with.” The school boat was seriously rocked by the presence of a policeman, starting with the question of whether or not he should wear uniform; the school wanted him in plain clothes, he felt he needed the protection of the uniform. “Kids are more hostile to a uniform but they won’t try it on so much. There’s less chance that they’re actually going to attack you.”

PC Smith was perturbed by what he saw as the school sweeping crime under the carpet - “serious sexual assaults, gang robberies, kids getting victimised day in, day out”. It’s a picture that will be familiar to many pupils. Crime and anti-social behaviour are on the increase in schools. In a Youth Justice Board survey of more than 5,000 secondary pupils, 60 per cent were afraid of being assaulted or robbed at school; 40 per cent were afraid of being bullied; and one in four admitted committing a criminal offence.

But heads and governors in struggling schools, desperate for pupils, do not want high-profile confrontations on site. PC Smith told the head: “You’ve got the chance to get those pupils some help through me because they won’t get help anywhere else. But they won’t get it because you don’t want the public to know. And those kids know it.” He describes a world in which a minority of children held other pupils, and junior staff, to ransom. “One teacher was headbutted, and had a broken nose and teeth. Another had her bag stolen. There were incidents all day and every day, and if the head had been supportive I could have cautioned the offenders, locked them up for a day, brought in restorative justice, and set an example. Instead, they get excluded for a week. The kids think, ‘we’ve stolen a bag, and we’ve got a week off school’.”

Matters came to a head when the officer, against the wishes of the head, arrested a pupil on site for demanding money with menaces. The school ejected PC Smith, and the force gave him no support. “I was left high and dry,” he says. “The head wanted someone there at 8am, at lunchtime and at the end of the day. He wanted a security guard. But I don’t see my role as hired muscle. You need a supportive headteacher - then it can be a brilliant scheme. You could build up a database of all these kids who get into trouble, and try to do something for them.”

A Home Office document on police and schools, Together We Can Tackle It, can be seen at www.homeoffice.gov.uk or ordered from DfES Publications, PO Box 5050, Sherwood Park, Annesley, Notts NG15 0DG

OFF THE RECORD

Young people are criminally responsible for their actions from the age of 10.But few under the age of 17 are ever charged.

Young people who tangle with police may receive either a reprimand, which goes on a police record until they are18, or a final warning from a youth offending team, which will look at the broader picture. If they offend again, they may be charged.