In the state of Florida there have been 23 death row exonerations since 1973. That is more exonerations in Florida than in California, Missouri, Mississippi, South Carolina, Indiana, Tennessee, Idaho, Kentucky, Maryland, Nebraska, Nevada, Virginia and Washington combined.
http://www.innocenceproject.org/understand/Unreliable-Limited-Science.php
The Absence of Scientific Standards
Unlike DNA testing, many forensic disciplines particularly those that deal with comparing impression marks and objects like hair and fiber were developed solely to solve crime. These disciplines have evolved primarily through their use in individual cases. Without the benefit of basic research or adequate financial resources, applied research has also been minimal.
In fact, many forensic testing methods have been applied with little or no scientific validation and with inadequate assessments of their robustness or reliability. Furthermore, they lacked scientifically acceptable standards for quality assurance and quality control before their implementation in cases.
As a result, forensic analysts sometimes testify in cases without a proper scientific basis for their findings. Testimony about more dubious forensic disciplines, such as efforts to match a defendants teeth to marks on a victim or attempts to compare a defendants voice to a voicemail recording, are cloaked in science but lack even the most basic scientific standards. Even within forensic disciplines that are more firmly grounded in science, evidence is often made to sound more precise than it should. For example, analysts will testify that hairs from a crime scene match or are consistent with defendants hair but because scientific research on validity and reliability of hair analysis is lacking, they have no way of knowing how rare these similarities are, so there is no way to know how meaningful this evidence is.
Just trying to make a point that although circumstantial evidence can and is used in many cases, it is obviously not foolproof, and when the circumstantial evidence is as weak (IMO) as it was in this case, I think a verdict of guilt would have resulted in an appeal and acquittal.
There have been 138 death row exonerations since 1973. That means that 1656 jurors unanimously convicted 138 innocent people to be executed. This is just death row exonerations, there have been hundreds of other exonerations where thousands of jurors wrongly convicted the innocent. Had this jury reached a verdict of guilt, I think KC would have joined the hundreds of wrongly convicted.
I think the jury in this case gave the correct verdict, because two of the key pieces of evidence was the air sample and single hair, although they passed the Frye hearing, I still think they lack the scientific standards needed to be used convincingly in a courtroom. JB and his witnesses successfully rebutted this evidence in my opinion.
As always, my entire post is my opinon only.