Police officers have no obligation to be honest with suspects. They may encourage someone to tell the truth. Suspects may have to swear to tell the truth under oath. However, a police officer who is carrying out an investigation does not always have to be honest.
For example, perhaps you and a friend have been accused of the possession of illegal drugs. The police have split you up to do the interrogation. An officer comes in to talk to you, then goes to talk to your friend, and then returns. The officer tells you that your friend confessed to everything and says that you should do the same to get the lightest possible sentence.
This could be true — but don’t assume it is. The officer could’ve entirely made it up on the spot. Your friend may have said nothing at all. Police officers will sometimes lie about the evidence that they have as a means of attempting to manipulate suspects.
So what should you do?
One of the best things to do is to remember that you have a right to remain silent. You do not have to answer questions in an interrogation. You do not have to incriminate yourself. Simply refusing to answer the questions does not mean that you are guilty. If you believe that the police are attempting to manipulate you, it is best not to answer their questions at all, in many cases.
You also have a right to legal representation. It may be wise to tell the police that you’d be happy to continue with the interrogation and clear your name, but that you’re not going to answer any questions until you have your legal team present. Make sure you fully understand all of your rights and legal options.