An arresting problem with a Birmingham paedophile

A letter from one of my daughter's schools described the man as posing a "considerable threat" and provided parents - and pupils - with a description of the attacker. There was an appeal to call the police should anyone have information that might lead to his detention.
The letter was informative and therefore reassuring, or as reassuring as it is possible to be in such circumstances.
Compare this with the letter sent to parents by the local West Midlands Police inspector. This referred to parents having concerns about "rumours circulating at schools." It went on to explain police were investigating "three incidents". There was "no specific cause for concern."
Having read this letter, I, as a parent, hadn't a clue what was going on.
When does a series of three sexual assaults become a "rumour"? Rumours are only dispelled by keeping people informed, not patronising them.
And what does "three incidents" mean? Had there been three sightings of the Yeti?
The letter did not even include a description of the offender. The police always harp on about the public being their "eyes and ears," aiding crime prevention and detection. This felt more likely a case of the informed leading the blind. Ignorance is not bliss. It creates confusion.
As an aside, I have no doubt that intensive efforts are being made to capture the pervert - who'll plead guilty, blame his troubled upbringing and get probation.