Chris McGreal reports: The charge on the police docket was “disrupting class”. But that’s not how 12-year-old Sarah Bustamantes saw her arrest for spraying two bursts of perfume on her neck in class because other children were bullying her with taunts of “you smell”.

“I’m weird. Other kids don’t like me,” said Sarah, who has been diagnosed with attention-deficit and bipolar disorders and who is conscious of being overweight. “They were saying a lot of rude things to me. Just picking on me. So I sprayed myself with perfume. Then they said: ‘Put that away, that’s the most terrible smell I’ve ever smelled.’ Then the teacher called the police.”

The policeman didn’t have far to come. He patrols the corridors of Sarah’s school, Fulmore Middle in Austin, Texas. Like hundreds of schools in the state, and across large parts of the rest of the US, Fulmore Middle has its own police force with officers in uniform who carry guns to keep order in the canteens, playgrounds and lessons. Sarah was taken from class, charged with a criminal misdemeanour and ordered to appear in court.

Each day, hundreds of schoolchildren appear before courts in Texas charged with offences such as swearing, misbehaving on the school bus or getting in to a punch-up in the playground. Children have been arrested for possessing cigarettes, wearing “inappropriate” clothes and being late for school.

In 2010, the police gave close to 300,000 “Class C misdemeanour” tickets to children as young as six in Texas for offences in and out of school, which result in fines, community service and even prison time. What was once handled with a telling-off by the teacher or a call to parents can now result in arrest and a record that may cost a young person a place in college or a job years later.