However, if there was a probable cause to search that person because they were somehow involved, or an eyewitness identified their involvement while the crime was happening, a police officer could search them. If law enforcement came upon a scene where a crime was in progress, they could enter and search a location or person within the location of the crime in progress without violating that person’s fourth amendment rights.
The history of the fourth amendment does not have a clear path. According to the history found in Search and Seizure and the Supreme Court, a study in constitutional interpretation,
“An understanding of the antecedent history of the Fourth Amendment is therefore important for an evaluation of the subsequent development of that amendment through judicial construction. History alone cannot, of course, provide the Supreme Court with clear guidance on all search and seizure questions up for decision, if only because the historical record is not always as clear as we should like it to be, and also because some issues raised under the Fourth Amendment such as the constitutionality of wiretapping or compulsory blood tests in criminal cases are of recent origin and could have been anticipated by those who drafted the Bill of Rights.” (p. 19 Landynski