In the wake of the 2009 National Academy of Sciences report, "Strengthening Forensic Science in the United States: a Path Forward," Many courts no longer accept the "absolutely sure" quality control system. Forensic science is searching for methods to measure the degree of certainty attached to a forensic scientist's particular methods of analysis, level of knowledge and training in the methods used, and the scope of subjective opinion in making a judgment about the processed evidence. Forensic science is being challenged to take a look at itself and be able to quantify probabilities and degrees of certainty about courtroom testimony based on forensic science. From a purely scientific perspective, where nothing is known with absolute certainty, this requirement may be proper, but for many veteran fingerprint or firearms experts, this less-than-certain approach is a problem, since they have been trained to believe that they have the knowledge and experience to use scientific principles to make warranted conclusions about the matching of two unique sets of fingerprints and bullets that are unique to particular guns. How do you measure the degree of certainty of the judgment of a person whose judgment is based on known scientific criteria, assuming that the scientific criteria have been established by the scientific method? This is the challenge currently facing forensic science.