Question

Humans share 99.9% of their DNA with each other. In 1-2 sentences, explain how DNA can be used to understand whether suspects are innocent or guilty of a crime?”

Answer 1

Forensic labs compare the variable parts of DNA (like STR regions) from crime-scene evidence to a suspect’s DNA: a close match strongly implicates that the suspect left the sample, while a non-match can exclude them. However, because DNA evidence is probabilistic and can be affected by contamination, transfer, or close relatives, a match is strong but not by itself absolute proof of guilt.