On TV, the moment usually comes as sort of an anti-climax — after the big car chase, the running through the streets, the jumping over fences and across rooftops, and maybe even the exchange of gunfire, the cops finally tackle their man, slap on the handcuffs, and say: You are under arrest. You have the right to remain silent… etc.
Even without the requisite chase scene, most people know that when you are being arrested, the law requires the arresting officer to recite the Miranda Warnings, informing you that you have the right to remain silent, that anything you say can be used against you in court, that you have a right to an attorney, and that if you cannot afford an attorney, one will be appointed for you. Unfortunately, real life is rarely as predictable as a TV script, and it is not always obvious — even to the police — when the time is right for reading your rights.
The key is whether you are being questioned in what is called a custodial interrogation. A police officer is not required to read your rights before simply asking questions. But in some cases, the court has found that even before a formal arrest, the defendant was for all intents and purposes already in a custodial situation. This is based on factors such as the setting and duration of the questioning, whether the behavior of the police implied an arrest was in progress (for instance, surrounding the suspect), and whether the person being questioned reasonably felt that he or she was not free to leave.
It has been successfully argued that statements the defendant made in such a situation were not admissible as evidence because the person should have been informed of the right to remain silent by that time. So if you find yourself in a similar situation, try to make note of exactly what was going on even before the actual arrest — it could be the key to your defense later on.