Unfortunately ( or fortunately, depending how you look at it) the police have been publicising cases themselves when they think that doing so may lead to other cases coming to light.
That is what they did in the Stuart Hall case. Hall initially strenuously denied any wrong doing. The publicity encourage other victims to come forward . The victims were all un known to each other but their stories were very similar, and Hall's Modus Operandi was established.
When he was charged, it was not with just the original complaint, but with a catalogue of crimes and he must have known the evidence was great as he admitted all the charges.
In Hall's case he was a guilty man, but what if the police wrongly suspect someone is guilty but aren't. Naming (or letting their name be known) could be devastating for an innocent man. The whole thing looks like guilty - until proven innocent. In many cases (not the recent celebs) the police have pursued people and have been wrong.