why would the police call me and not leave a message

Police may call and not leave a message for several reasons: they might want to extract information or arrange a meeting without alerting others easily, they may have tried calling a suspect they intend to arrest and prefer a direct conversation, or avoid leaving messages as a tactic so you call back without suspicion. Additionally, some calls may be from detectives wanting to gather information or confirm suspicions, and sometimes police calls come from blocked or no-caller-ID numbers which are not set to leave voicemails. In any case, if contacted by police, it is generally advised not to call back immediately but to consult with a lawyer before engaging, especially if there is any suspicion of being involved in a crime. Ignoring the call does not stop police actions; they may attempt other means to reach you or even arrest if necessary. If unsure whether the call was legitimate, contacting your local police department by a known number to inquire can be a safe step.