They already do some limited DNA collection. Specially in family based petitions, such as parents petitioning children. The problem here is their are no regulatory laws saying how that DNA will be stored, for how long it will be stored, how it can be used, and whether it can be used for other cases, or shared with other government agencies. You gotta remember we leave our DNA everywhere, hair, spit, smoking a cigarette, etc etc. And while DNA is factual 100% their are ways to interpret its use and where and when it was found to find you guilty of a crime if it is shared with other agencies. That's what scares me. Not too long ago their was a case of a guy who had gone to the hospital in an ambulance, that same day, same ambulance carried a gunshot patient to the hospital who later died. 1st person to be in the ambulance was charged with the crime because their DNA was found in the decreased person's body. And although released later on, because their was camera footage and hospital records, DNA evidence can be misrepresented. Very slippery slope.