Often times police will attempt to engage you in conversation to gauge whether or not you are under the influence of alcohol. The truth is that you are only required by law to provide biographical information (name, address, date of birth, etc.). Beyond that, you have a right to decline to answer questions. Keep in mind, however, that you should never argue with the police. Always be polite and respectful.

Why Are Grand Jury Proceedings Secret? Who Has the Authority to Unseal Them?
Grand juries play a critical role in the U.S. justice system. They decide whether enough evidence exists to bring criminal charges, often in high-profile cases