What is the rule that forbids the use of illegally obtained evidence in a criminal trial?

The Exclusionary Rule is a legal principle that ensures any evidence obtained through violations of a person's constitutional rights, particularly in regards to unlawful search and seizure, cannot be used in court against that individual. This rule is pivotal in maintaining the integrity of the legal system and protecting citizens from unlawful government actions. It deters law enforcement from conducting illegal searches or obtaining evidence improperly by rendering such evidence inadmissible in court.

This approach promotes adherence to constitutional protections, ensuring that due process is upheld in criminal proceedings. By requiring evidence to be gathered legally, the Exclusionary Rule reinforces the idea that the end does not justify the means when it comes to law enforcement practices.