Mapp v. Ohio, , was a landmark case in criminal procedure

Criminal procedure

Criminal procedure refers to the legal process for adjudicating claims that someone has violated criminal law.-Basic rights:Currently, in many countries with a democratic system and the rule of law, criminal procedure puts the burden of proof on the prosecution – that is, it is up to the...

, in which the United States Supreme Court

Supreme Court of the United States

The Supreme Court of the United States is the highest court in the United States. It has ultimate appellate jurisdiction over all state and federal courts, and original jurisdiction over a small range of cases...

 decided that evidence obtained in violation of the Fourth Amendment

Fourth Amendment to the United States Constitution

The Fourth Amendment to the United States Constitution is the part of the Bill of Rights which guards against unreasonable searches and seizures, along with requiring any warrant to be judicially sanctioned and supported by probable cause...

, which protects against "unreasonable searches and seizures," may not be used in criminal prosecutions in state courts, as well as federal courts.
When the Cleveland Police Department received a tip that Dollree Mapp and her daughter were harboring a suspected bombing fugitive, they immediately went to her house and demanded entrance.