The supreme court ruled in miranda v. arizona that
evidence seized illegally cannot be used in a criminal trial
states must provide lawyers to poor criminal defendants
a suspect cannot have an attorney present during police questioning
police must inform suspects of their rights before questioning

The answer is: that evidence seized illegally cannot be used in a criminal trial.

The Miranda rights (  also known as Miranda warning ) is an oral notification given to a person in police custody. That person is usually accused of committing a crime or criminal offence.

The accused is given the right to remain silent, meaning they can refuse to answer any questions or give information to law enforcement officials. They also have the right to have an attorney present during their interrogation. If they can not afford one, the court will appoint an attorney for them.

The Miranda warning is only given if the individual in question is about to be interrogated, and not if arrested only.

This warning was established as part of the Fifth Amendment right against  self incrimination. Any evidence obtained from an accused person without them being given the Miranda rights can not be used as evidence in court.

Miranda v. Arizona was a landmark decision of the U.S. Supreme Court in 1966. It ruled that statements made by the defendant in an interrogation would only be admissible at trial if the individual was aware of his rights ( silence, attorney ), and that the individual understood the rights and voluntarily agreed to them.