I wish that I didn't want to like this post a thousand times.
We HAVE to demand better of our legal system from evidence collection on the scene, all the way through local LEA, transport to labs, evaluation, and possible prosecution, IMO.
EVERYONE, including first line officers, detectives, FIRE-FIGHTERS, EMS, and ER staff need to be trained on the importance of scene and evidence preservation, chain of custody etc. (IMO)
Obviously, human survival takes precedence, but as soon as it is established that the victim of a crime is deceased, securing the scene and evidence should be of paramount importance, IMO.
I think that funding forensic science, both from an evidentiary, and psychological perspective should be a priority for local, state and national governments, but that's just my opinion.