The Highland News reports that Drakies Primary School in Inverness, Scotland, has spent £1000 on fingerprint scanners for their school library.
The below comment is, as far as I know, the first mention in the media of police having accessing school fingerprint databases. Police can use children's biometric databases in England and Wales without informing parents. It does state here that the police have to get permission from the school and parents, Scottish law is different to English and Welsh law so this may well be the case in Scotland - but not in England and Wales (see questions 50 and 51).
... a spokeswoman for the National Policing Improvement Agency said: "If the police have reason to suspect a child has committed a crime then as part of their investigation with permission of the school and the parent, the police can request access to the data if they have reason to believe it will help them with their investigation."
There is no relevance to the argument that fingerprints aren't stored - a biometric identifier is stored which carries the exact same implications as if a fingerprint was stored.