362 Forensic dentistrystating or connoting absolute certainty (“Mr. X bit Ms. Y,” “only one person
in X million or billion could make such a mark,” or “indeed and without
doubt”) are inappropriate and scientifically unsupportable. The meanings
of reasonable scientific, medical, or dental certainty are consistent with the
legal phrase “beyond reasonable doubt.” The word reasonable in both terms
implies that the person considering the question did so “to the best of his or
her ability and after due consideration.” A reasonable doubt must not be an
imaginary or frivolous doubt, nor should it be based upon bias, sympathy,
or prejudice. Rather, it should be based on logic, reason, and common sense.
Determinations with reasonable dental/medical/scientific certainty, like
determinations beyond reasonable doubt, should be logically derived from
the evidence or absence of evidence. The burden on the prosecution expert in
a homicide case is a grave one indeed. As we have seen from the tragic errors
of the past, a misidentification of a bitemark can lead to the incarceration of
an innocent person and, consequently, freedom for the guilty person, who
can continue to kill. The consequences to the expert who misidentifies a bite-
mark or gives improper testimony can be terrible, legally, financially, emo-
tionally, personally, and publicly. They may be barred from giving bitemark
testimony in a court of law in the future. The expert may be subject to legal
action brought by the person wrongly accused/convicted. He or she may be
exposed in the media. Accounts may be written in newspapers, weblogs,
magazines, and books, generating public hostility. As a result, bitemark evi-
dence may be referred to as a “junk science” or worse. All this is in addition
to how the expert must feel knowing he was even partly responsible for the
incarceration of an innocent man. These are grave consequences for errone-
ous analysis and testimony. The defense expert has just as much responsibil-
ity to be truthful and objective as the expert for the prosecution, but errors
by defense experts do not carry the same legal, financial, or public burden
as the errors by a prosecution expert. Defense expert errors may contribute
to a guilty suspect being freed, but the defense expert will rarely be publicly
humiliated or sued. Defense expert errors are perceived to be less serious
than those made by prosecution experts, partly because of the belief that it is
better for many guilty persons to go free than to convict one innocent man.
In 1970 the U.S. Supreme Court ruled that the highest standard of proof is
grounded on “a fundamental value determination of our society that it is far
worse to convict an innocent man than to let a guilty man go free.”^83
Expert testimony in civil bitemark cases differs from that in criminal
cases. The burden of proof is different, requiring only “preponderance of
evidence,” not “beyond reasonable doubt.” Expert testimony for a plaintiff
if in error will never cause an innocent person to lose his life or liberty,
only his money and maybe his reputation. The expert witness will rarely
be the subject of legal action after a trial unless it can be proven he or she
knew facts and lied about them. Bitemark testimony in tort cases is rare,