单选题
In a certain municipality, a judge overturned a suspect's conviction for possession of an illegal weapon. The suspect had fled upon seeing police and subsequently discarded the illegal weapon after the police gave chase. The judge reasoned as follows: the only cause for the police giving chase was the suspect's flight: by itself, flight from the police does not create a reasonable suspicion of a criminal act; evidence collected during an illegal chase is inadmissible; therefore, the evidence in this case was inadmissible. Which one of the following principles, if valid, most helps to justify the judge's decision that the evidence was inadmissible?