Generally speaking, unless you tell the police they can come into your home and conduct a search, they have to get a warrant.
However, don’t make the mistake of thinking that a single warrant means they can just do as they please. The truth is that the warrant may have a limited scope, and the police have to abide by those instructions.
A judge will issue the warrant with specific parameters
Remember, a judge gives out the search warrant, and they do it after the request is made by the officers. The judge decides if it’s reasonable to conduct a search based on other evidence. They only have to authorize as much of a search as they believe is just.
For instance, maybe the police got a search warrant for your home. It contains your address and says that they can search your home and your garage. While at your home, the officers notice that you have a second out-building on your property. They want to take a look. You can consent to such a search if you want, but they can’t necessarily look in it just because they have the initial warrant. They may need to get another one. If they search there anyway, the evidence they uncover could be thrown out of court.
Protecting your rights against illegal searches is part of your defense
Understanding search warrants is especially important in drug cases, where the police have very specific goals regarding what they want to find. If they violate your rights by overstepping the bounds of the warrant or operating without one entirely, it can drastically impact your case and you must know what steps to take.