[per loin]

The more information the public has, the more likely it becomes that the killer will be caught. But police departments like to protect their turf, so they keep facts secret. Of course, when the facts are kept secret, rumors and misinformation spring forth to confuse the situation, and make it more difficult for the public to know what to keep an eye open for and what to report.

[js1138]

Everything you say is true, but clues that would encourage a copycat do not need to be made public in the early stages of an investigation. It is also possible that these particular clues are deliberate distractions.