Which type of evidence tends to show that a defendant is not guilty of the crimes charged?

Exculpatory evidence is critical in legal contexts as it specifically refers to information or material that may absolve a defendant from guilt or demonstrate that they did not commit the crime for which they are being charged. This type of evidence plays a vital role in upholding the principle of presumption of innocence. It can include witness testimonies, alibi confirmations, or any factual data that indicates the defendant's non-involvement in the alleged criminal activities.

The other types of evidence mentioned have different purposes. Mitigating evidence is typically related to the character or circumstances surrounding the defendant and is used to argue for a lesser penalty rather than to prove innocence. Impeachment evidence focuses on discrediting the credibility of a witness, pushing the narrative towards questioning the reliability of their testimony rather than directly proving a defendant's innocence. Material evidence, on the other hand, pertains to evidence that has relevance and significance in proving a point in the case, but it does not necessarily establish innocence. Thus, exculpatory evidence is the type that directly supports a claim of not being guilty.