Our advice is to always respectfully refuse to speak to the police. Many times people feel the need to fully cooperate with the police and do whatever they ask, but invoking your constitutional rights does not mean you are being uncooperative, it means you are protecting yourself to make sure you don't say something by accident that can be used against you later. You can be polite, respectful, and cooperative while saying “I would just feel more comfortable having a lawyer present so no I do not wish to answer any questions.”
Your silence and refusal to answer the questions the police would like to ask you cannot be used against you in court at all. If you do talk to the police, however, everything you say can and will be used by the prosecution to try to convict you. This is why silence is always your best course of action.