Don't get drawn into conversations with the police. Apparently innocent remarks can be used against you. You do not have to say or write anything, or sign any statement. You have the right to refuse to answer all police questions.
Most people are better off remaining silent when being questioned.
If the police suspect you have committed any offence you can be arrested if you refuse to give your name and address, or if they aren't satisfied with the address you have given. If in doubt, do and say nothing until you have contacted your solicitor, Release, or the Duty Solicitor. If anything you ask for is refused, ask why and remember the reason given. As soon as possible make full notes of what has happened and give them to your solicitor. These can be used as evidence in court.