Fourth Amendment rights

The fourth amendment states that a search warrant is needed before searching a house. I think that it is unnecessary to have a search warrant because if someone is suspected of an illegal action than, they can be accused and caught. And if it turns out they are not guilty, then they are not guilty. On the terms that it is violating rights, if someone is caught, then nothing negative has come out of it. And if they search a house and don't find anything, then at least they took the risk. Another reason for disagreeing is that, if they do go into a house without a search warrant and they find evidence, they cannot use it in court. I disagree with this because if something is indeed found in the house illegally, then it will be taken care of.