The exclusionary rule prevents what type of evidence from being used in court?

The exclusionary rule is a legal principle that prohibits the use of evidence in court that has been obtained in violation of a person's constitutional rights, particularly the Fourth Amendment, which protects against unreasonable searches and seizures. This rule is foundational in upholding the integrity of the judicial system and ensuring that law enforcement adheres to constitutional standards in gathering evidence.

When evidence is obtained unlawfully, such as through an illegal search without a warrant or consent, or through coercion, it cannot be used in court proceedings against the defendant. The rationale behind the exclusionary rule is to deter law enforcement from engaging in illegal practices by making any evidence obtained from such actions inadmissible. This helps to maintain public confidence in the legal system and protects the rights of individuals against government overreach.

In contrast, other options present scenarios that do not typically fall under the exclusionary rule. For instance, evidence obtained through a confession may be admissible if the confession was made voluntarily and in compliance with the suspect's rights. Additionally, circumstantial evidence can still be admitted in court as long as it has been obtained legally. Lastly, evidence obtained with a warrant is usually considered lawful, provided that the warrant was issued based on probable cause, which does not invoke the exclusionary rule.