I am unhappy about the fact that a senior teacher can interrogate a child about something that he has done outside school, in the prescence of a police officer, without first informing the parents and it can then become recorded by the police. Police are not allowed to interview children in this way - but it seems that if the teacher does the interrogation in the presence of a police officer they can circumvent his rights and protections under the law.
Meanwhile the girl that circulated the images...?
"Sexting" is, unfortunately common practice amongst UK teenagers. This includes taking pictures of themselves involved in sexual acts and sending them to friends.
Schools have a responsibility to educate children about the dangers of this. Why?
Firstly because they teach PHSE (sex education) and if they do it well, this issue should be covered, and covered by the time the kids are 11 or 12. (Don't do it, why, what if someone else does it, what if someone asks you to do it etc etc)
Secondly because schools need to have up to date IT use policies to inform both staff and students about what is and is not proper use of school equipment, school software etc.
Thirdly because schools should have an anti-bullying policy - and be active in combatting bullying of all types.