The quote below comes from the Supreme Court ruling in Mapp v. Ohio (1961):
We hold that all evidence obtained by searches and seizures in violation of the Constitution is, by that same authority, inadmissible in a state court.
Source: http://www. Law. Cornell. Edu/supct/html/historics/USSC_CR_0367_0643_ZO. Html
Why did the Court make this ruling?
to ensure that criminal defendants were given a speedy trial
to provide protection for the rights of every citizen
to increase the power of the federal government over the states
to allow all citizens to make choices without government interference