Strangers drew a knife on her, demanding money. We called the police and comforted her as best we could.

You felt for the poor woman. Primal responses take over. You don’t want procedures and statements, you want revenge.

Just like teachers, people have unrealistic expectations of the police. We are fellow professionals often dealing with the same things. The difference is that the children treat teachers with far more respect.

We don’t call them that often. When we do they know it must be serious. And I suppose the students know that too, because a frisson of excitement shivers round the school when a police car pulls in. Then boys coagulate into a gang, watching, enveloped in a haze of hostility.

Affable and co-operative young men instantly adopt a snarling defiance. It always makes us feel better because teachers don’t have to face quite the same range of hostility. I once taught in a school that was next to a police station. They called on our help far more frequently than we called on theirs. Kids hiding under police cars, chasing round the car park, barking at the Alsations. Please come and get them.

Their rules of engagement are different, and more importantly the kids view them differently. We have to establish a relationship with the students in the school, no matter how unpalatable that may sometimes appear. But the police are nothing more than the physical manifestation of the society that tries to hold them in.

Generally, in dealing with problems, they are far more meticulous than we are. We are able to respond more instinctively sometimes. But it is really easy for parents to waste their time.

Those who feel we have not dealt with things as punitively as they would like are straight off down the station. It is usually the more difficult families who are prepared to do this. The police are part of the fabric of their lives. They enjoy the moment when, for once, the boot appears to be on the other foot. So they complain about the school for a while and some poor officer has to come up and check it out.

Of course, the kids are fascinated by all the toys, the equipment strapped to the clever belt, the radios. But for many the police are the enemy and they make themselves feel good through petty acts of defiance. They quite like teachers by comparison.

Ian Roe is a teacher in north Wales