It's funny, I was just having this discussion. If the perp has been arrested before yes, by law, they are required to submit DNA. Hopefully they have a POI in mind and do not need to fall back on this.
Forensics & DNA are a good thing, Billiam.. After the Holly Bobo abduction the TN legislature passed the familial dna law which went into effect 01/01/2012. This will more than likely be the catalyst for justice in her case, IMO. All they need is a family members dna to nab a suspect.
Today, most jurors are suffering from the CSI Effect & expect forensic evidence, as we all have witnessed lately.
The dna tests have also exonerated innocent folks that were convicted & sent down the river due to circumstantial evidence & twelve people who were picked to judge who had the best attorney..