Wow, thanks for the information as to the Action of the Attorney General. I agree there is no legal definition for the term, “reasonable degree of scientific certainty”. My question is what does the person say if the court indicates they will be using reasonable certainty as a point to determine the level of the quality of the opinion, from which a determination will be made as to the person testifying. In the US Eighth Circuit case that is the foundation reasonable certainty it was stated, “If the witness, based upon his background skill, possesses extraordinary training to aid laymen in determining facts and if he bases his answer upon what he believes to be reasonable scientific or engineering certainty, generally the evidence should be admitted, subject, of course, to the cross-examination of the adversary. The weaker the scientific opinion or the less qualified the expert, the more vigorous will be the cross-examining attack and undoubtedly the less persuasive will be the opinion to the trier of fact.” For decades the courts have used this decision when evaluating the reliability of a person’s opinion.

I understand the Attorney General’s action and the opinion of the National Commission on Forensic Science. I can go along with what they are saying. My question has always been what is the number behind the term “degree of scientific certainty”.

There is a legal definition for the term more probable than not. More probable than not means that upon consideration of all of the relevant evidence and materials, a preponderance of the evidence and materials supports the finding.

I agree with you about the 49-point swing. That is why I would suggest that in 921 they use the definition above and drop the point swing. I think the definition above is more inline with your uniquely consistent with the evidence. I totally agree with you about the oversight. At one time the NFPA had a section that dealt with these issues and was not necessarily the committee’s responsibility.

Jim Mazerat
Forensic Investigations Group