What principle is established in Wong Sun v. U.S?

The principle established in Wong Sun v. U.S. is the "fruit of the poisonous tree" doctrine. This legal concept holds that evidence obtained from illegal searches or seizures, or as a direct consequence of an illegal action, is inadmissible in court. In this case, the Supreme Court ruled that not only must the initial evidence obtained through unlawful means be excluded, but also any secondary evidence that is derived from that illegal evidence.

The case involved the unlawful arrest of Wong Sun, which led to the discovery of additional evidence. Since the initial arrest was deemed unlawful, the subsequent evidence was also ruled inadmissible. This principle is crucial in protecting individuals' Fourth Amendment rights against unreasonable searches and seizures and ensuring that law enforcement authorities follow legal procedures when obtaining evidence. It reinforces the idea that the government cannot benefit from its own illegal actions, thereby promoting lawful conduct by law enforcement.

Understanding this principle is vital for police officers and legal professionals, as it underscores the importance of conducting searches and seizures legally to uphold judicial integrity.