The Fourth Amendment states that "no warrants shall issue, but upon probable cause. Plain View – When evidence can be viewed in the open, no search warrant is required.Police in Pennsylvania can enter your home without a warrant if they can see evidence of criminal activity in plain view from outside the home. Learn about search and seizure in PA and how a lack of a warrant can affect the outcome of your case. Call Travis Law for help. What Does the Fourth Amendment Mean? Under the Fourth Amendment, police can engage in reasonable search and seizure. In Pennsylvania there is a presumption that any search of an individual's home without a warrant is illegal, but there are exceptions. The Fourth Amendment states in a nut shell that we shall be free from unreasonable searches and seizures. In the Pennsylvania case, Commonwealth v.