[AnthonyMouse]

The tests generally choose markers that tend to differ between different people rather than the ones that tend to differ between people and animals.

But even then, people use percentages as if everyone's DNA was independent. Which it isn't. Blood relatives have similar DNA.

The one thing DNA is really good for is excluding people. If you have the rapist's DNA and you accurately test it against the suspect's DNA and it doesn't match, it's not them.