The DNA sample in a vacuum doesn’t mean too much in a sexual assault case. Although you can prove race, gender etc you can’t prove that it is the defendant’s DNA without his sample. Typically, you compare a DNA sample with another DNA sample(s) that is taken separately from the original DNA sample.
The DNA sample is alleged to be evidence from a rape.
It doesn’t need to prove anything. It could either rule Donald Trump in or out as a possible source.
Since doing this would be so easy to do, assume DNA analysis has already be run on the sample (if it really exists) and the result doesn’t lead to Donald Trump.
He is smart not to give a DNA sample. She could have obtained a casual contact sample (some one bumped into him at a party and sold her the sample). Make her prove the sample was promptly registered with the police and in their custody documented.