An unreasonable search and seizure is one that is done without a reasonable suspicion that the person has engaged, will engage, or is attempting to engage in criminal activity. The police must have more than a hunch. They must have more than merely a suspicion. A reasonable suspicion must be supported by objective facts that there is criminal activity. An arrest must be based on probable cause, but the police often stop and search a citizen before they arrest them. To do this under the 4th Amendment there must be a reasonable suspicion of criminal activity. As soon as you are detained or are not free to leave, your 4th Amendment right to be free from unreasonable searches and seizures arises.
It is important to speak to an attorney about your specific situation to see if your rights were violated. The police often attempt to characterize detaining you as consensual so that the 4th Amendment doesn’t apply. Most people would not feel free to leave if they were approached by the police and asked questions. Whether you were detained or whether it was just a consensual encounter with the police depends on many things. You should consult an experienced criminal attorney to find out if your 4th Amendment rights were violated with an illegal detention and an unreasonable search and seizure. If the court determines that your rights were violated, all of the evidence against you in your case may be thrown out or suppressed and your case dismissed.