During an interrogation with police, you do not have to say anything because of your right to silence. But that does not mean officers will not continue to talk to you. They can say just about anything to get you to talk.
The Innocence Project explains law enforcement may lie to you, but you cannot lie to them. The law says officers do not have to be truthful during an interrogation, but lying to police is illegal for you to do.
When an officer takes you into an interrogation room, his or her main goal is to get a confession from you. You should know your legal right to silence at this point, which means that you do not have to answer questions or provide any information because the U.S. Constitution grants you the right not to provide testimony against yourself. Anything you tell officers becomes evidence the prosecutor can use against you in court.
The Constitution does not provide you with the right to tell officers untruthful information. Doing this is against the law. So, if you do not wish to tell the truth, you should not speak at all.
Lying is a common interrogation tactic. Officers do it all the time. They will try to use lies to manipulate you and get you to start talking. It is a legal method they can use. You cannot use it as a defense. For example, you cannot say the only reason you confessed is that a cop told you your friend already told them what happened.
Law enforcement does not have a blanket right to lie about everything, though. There are some exceptions. They cannot tell you untruthful things about your rights or use lies in a coercive way. Coercion is illegal and could be something you can use as part of your defense.