No, you do not. Under most circumstances, the police are required to obtain a search warrant before they can conduct a search of your home, or there must be a valid arrest before they can search your vehicle. Warrants can be defective and thereafter possibly successfully attacked. If you voluntarily allow the police to search, you’re giving up a valuable right and getting nothing in return.
The police are not required to tell you the truth. They will trick you any way they can. Which is why talking to them is not a good idea. However friendly and interested in your story as they might appear, their real goal is not to sort out the truth but to gather evidence against you. And, contrary to popular misconception, a police officer does not have to admit he is a cop if you ask him!
The short answer to this is probably yes. If you’ve been charged with a crime or are being investigated concerning one, it is important to have a qualified criminal defense lawyer at the earliest possible stage. A good lawyer can protect you from overzealous police investigators and prosecutors. And it’s important to keep in mind that you don’t just need any lawyer, you need one with experience in the kind of case you’re dealing with and in whom you believe in and trust.