I know a public defender. DNA like samples are expensive to run test on. So that cost for a dead body has little justidication on the budget, IMO.
The show CSI made it easier for pub defenders to get their clients off cause everyone ask for DNA and knows about it and the state is too cheap to run them for every case.
Sounds like that's a moot point and irrelevant to this case:
"Cassie is upset the suspect was released, especially since she said police told her they found him using DNA."
Obviously, the test was already run on samples from the crime scene, and the suspect was identified from a DNA database. I have a sneaky suspicion he's in the system due to previous sex crimes.
If the Cops can't determine whether the assault was pre- or post-mortem, maybe looking at his previous arrests would indicate whether he's assaulted living victims before. If so, it's unlikely he just happened to stumble upon a recently deceased individual and decided to take advantage of someone/something who couldn't fight back.
Either way, the guy is sick, and the evidence sounds convincing.