Violence, drugs, arson and sex offences were just some of the crimes committed in Lancashire's schools last year.
A request under the Freedom of Information Act (FOI) showed most of the 631 recorded crimes involved burglary, theft and criminal damage, with around one third linked to burglaries.
However, police say the way some incidents are having to be recorded means the figures are slightly misleading.
But the FOI request also revealed some Lancashire police divisions recorded complaints of acts endangering life, drug possession and arson - along with 12 offences of a sexual nature.
In one case, recorded as an "act with intent to endanger life", a 12-year-old boy at a school near Preston, was hiding behind a toilet door when a 14-year-old boy kicked it open.
He deliberately slammed the door against him seven more times causing him to suffer a broken and dislocated wrist. He was charged with a Section 20 wounding.
Police say national reporting standards for crimes in schools mean some incidents appear more serious than they actually are.
For example, a bruise must still be recorded as "actual bodily harm" to comply with national ethical crime recording standards.
Det Chf Insp Lee Halstead, of Preston Police, said: "The police have a duty to record allegations of crime made by any member of the public.
"Following investigation some crimes can be found to be less serious than first reported and the criminal justice system has developed over the years to take account of this by introducing several layers of punishment from simple informal resolutions through to the more severe custodial sentences."
Preston's division showed a drop in crimes reported in schools with 60 compared to 160 the previous 12 months that had included three woundings and seven reports of actual bodily harm.
One pupil was charged with possession of a knife in school, and two other youngsters were dealt with for sexual assaults on a girl aged over 13.
Four reports of actual bodily harm were made.
Les Turner, Lancashire county secretary of the National Association of Headteachers, said: "I don't think there's any more violence in schools now than 10 or 20 years ago.
"What has happened is the reporting mechanisms have been changed and things are now being reported which weren't in the past."
'Valued and safe'
County Counc Susie Charles, cabinet member for children and schools, said: "We take safety and security extremely seriously and work closely with schools and the police to ensure that our schools are safe and productive places of learning.
"We are never complacent, but with more than 630 schools and a school-age population of around 190,000, it is inevitable that a small number of incidents occur.
"Thankfully, serious crimes in school in Lancashire are very rare, and more rigorous reporting procedures can mean that smaller-scale incidents must be recorded alongside more serious ones.
"Performance in Lancashire's schools regularly outstrips the national average and our most recent survey of secondary age pupils reinforces the view that our schools are well-ordered communities where the great majority of pupils feel valued and safe."
A police spokesman said: "Safeguarding children and young people is a priority for the Constabulary and we work in partnership with schools and the Local Educational Authority to ensure schools are safe places for pupils to attend.
"Incidents of serious crime in schools in Lancashire are rare, and when they do occur they are vigorously investigated."
For more on this story see the Lancashire Evening Post