Do The Police Have To Advise Me Of My Rights?
The Constitution of the United States protects us against self-incrimination. We cannot be required to testify in a court of law. Out of this concept case law has developed that expands this principle to police questioning. You are not required to answer questions and the fact that you choose not to answer cannot be used against you.
Before you are arrested and not in custody any answers that you give the police can be used against you and to incriminate you even if you were not advised of your rights. The requirement of a waiver of your constitutional rights for answers to be admissible in court is a custodial right only.
If you are arrested police always advise you of your rights in the hope that you will waive your right to remain silent and have an attorney present. Then they can question you after a proper waiver and your answers can be used against you.
Even though police departments have a uniform policy of giving the so-called Miranda warning, the advisement of rights, there actually is no legal requirement for it. There is no legal penalty for them not advising you. However, if they question you without a waiver your answers are not admissible in court and any information that the get from your answers that leads to discovery of evidence will be excluded from the case against you.