What does DNA evidence reveal in criminal investigations?

DNA evidence is a powerful tool in criminal investigations because it can uniquely identify or exclude individuals based on their genetic makeup. Each person's DNA is distinct (except in the case of identical twins), making it possible to match DNA found at a crime scene with that of potential suspects or known individuals. This capability can be crucial in confirming someone's presence at a scene or ruling them out, which can significantly affect the direction of an investigation.

While DNA can contribute to understanding certain aspects of a case, such as corroborating an alibi indirectly by showing that a suspect's DNA was not present at a crime scene, it does not inherently provide information about the motive behind a crime nor does it assign blame. Instead, it serves primarily as a means of identification or exclusion in the context of evidence, making it an essential aspect of modern forensic science.