Why do you think dna evidence is so important in many court cases? what changes has it made to forensic science?

I'm not sure how detailed this needs to be but I'll try. DNA is a self-replicating material and the carrier of genetic information. 99% of DNA between to people will be identical but it's the 1% that makes us unique (honestly it's more like 99.9% and 0.01% but I wasn't sure if that's completely right). The more closely two people are related, the more similar their DNA will be. That's why DNA has been used as a powerful tool in court cases. DNA can be found at a crime scene and then be used to identify a culprit, victim, witness, or accomplice. Forensic scientists are able to take small biological samples and analyze them to create a DNA profile. Usually the best evidence occurs when a person's DNA is found where it isn't supposed to be. They can find DNA on objects such as: bottles, weapons/tools, hairbrushes, condoms, dirty laundry, etc. I'm not sure if this is what you were looking for but I hope it helps!