Comment by BlackFly

They are obviously allowed to discuss certain aspects, "We have a suspect," "We have our best detective, Sherlock Holmes, working on the case," "Here is a photograph of our suspect, please contact us if you have any information regarding the suspect."

Then there are other aspects that they would be prohibited from sharing in some legal jurisdictions, that hinge on privacy law (divulging sensitive but irrelevant details regarding the suspects alibi that they learned by interviewing the suspect) or on affecting potential jury members.

Instead they use the idea that they aren't allowed to share any information to just avoid answering questions.