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FBIJUN09.TXT
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1990-06-29
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June 1990
DNA TESTING AND THE FRYE STANDARD
By
Robert A. Fiatal, J.D.
Special Agent
Legal Instructor, FBI Academy
The ability to identify a certain individual as the
perpetrator of a specific criminal act through DNA analysis and
comparison is undoubtedly a revolutionary investigative procedure
for law enforcement. This technique, which isolates and measures
the variations in the DNA structure of unknown blood or semen and
compares those variations with the variations in the criminal
suspect's DNA, (1) possesses particular value in the investigation
and prosecution of violent crimes, such as rape, homicide and
aggravated assault. The results of DNA examinations can
effectively rebut alibi defenses, corroborate the accuracy of
what otherwise might be questionable eyewitness identification,
and correspondingly produce more guilty pleas. (2) Conversely, it
can exonerate the innocent. (3) For this procedure to be truly
effective in the criminal justice system, however, expert
opinions and conclusions based upon DNA identification must be
admissible in criminal prosecutions.
Comparisons and conclusions based upon this scientific
technique are strong, if not overwhelming, proof of guilt, and
prosecutors, investigators, and forensic scientists should
anticipate strong defense objections to the admission of such
testimony at trial. Therefore, all examined specimens must be
obtained in compliance with constitutional standards and
maintained in a manner that precludes contamination and assures
a strict chain of custody for later authentication and
identification. Moreover, since conclusions from this
sophisticated testing process are based upon what some courts
have viewed as the relatively novel application of scientific
techniques and procedures to forensic science, the law
enforcement community should be prepared to satisfy specific
admissibility requirements not normally associated with the
introduction of other types of expert testimony.
The purpose of this article is to acquaint the police
officer, prosecutor, and forensic scientist with these
anticipated admissibility requirements in order to assist them in
their law enforcement and prosecutorial functions. One should
remember, however, that the ability to meet these requirements is
almost entirely dependent upon the ability of expert witnesses to
convince the courts, through their testimony, that these
conditions have been fulfilled. It is also incumbent upon these
experts to convince the courts that the procedures used in a
particular case were conducted in a reliable manner.
ADMISSIBILITY OF NOVEL SCIENTIFIC EVIDENCE
When assessing the admissibility of novel scientific
evidence, some courts limit their review to the application of
the traditional evidentiary test of relevancy. Under this test,
scientific evidence is admissible if the testifying expert is
duly qualified, the expert's opinion is relevant and will assist
the fact finder, and the testimony is not so prejudicial as to
outweigh its probative value. (4) For example, in United States v.
Baller, (5) the U.S. Court of Appeals for the Fourth Circuit
applied this test of admissibility to testimony relating to the
then new technique of voiceprint or spectrographic
identification. Because that expert testimony was found by the
court to be relevant and not overly prejudicial, it was admitted.
Most jurisdictions, however, apply the more stringent Frye
standard when judging the admissibility of evidence derived from
a relatively new scientific procedure. Based on the decision in
Frye v. United States, (6) these courts also require that the
theory underlying the technique, as well as the technique
itself, be generally accepted or commonly recognized by
scientists in the relevant scientific community. (7) Most courts
that use the relevancy standard also deem the general acceptance
or common recognition of a technique to be important factors in
determining if evidence is relevant. (8) For example, the Supreme
Court of Oregon determined that trial courts in that State should
consider the following factors when assessing the relevancy of
evidence based upon a new scientific approach: 1) The testifying
expert's qualifications; 2) the existence of specialized
literature about the procedure; 3) the use of the procedure; 4)
its potential for error; and 5) its general acceptance in the
relevant scientific community. (9)
Accordingly, prosecutors, forensic scientists, and law
enforcement officers in all jurisdictions should be prepared to
satisfy the Frye prescription when introducing evidence
concerning the results of DNA examinations, even though their
particular jurisdictions may not specifically adopt the Frye
standard.
THE FRYE STANDARD
In Frye, the U.S. Court of Appeals for the District of
Columbia Circuit reviewed the admissibility of evidence based
upon a relatively primitive polygraph technique and ruled as
follows:
``Just when a scientific principle or discovery crosses
the line between experimental and demonstrable stages
is difficult to define. Somewhere in this twilight zone
the evidential force of the principle must be recognized,
and while the court will go a long way in admitting
expert testimony deduced from a well-recognized
scientific principle or discovery, the thing from
which the deduction is made must be sufficiently
established to have gained general acceptance in the
particular field in which it belongs.'' (10)
Applying this standard, the court found that the questioned
polygraph procedure had ``not yet gained such standing and
scientific recognition among physiological and psychological
authorities as would justify the courts in admitting testimony
deduced from the discovery, development, and experiments thus far
made.'' (11) Therefore, in order for the government to introduce
conclusions and opinions based upon a novel scientific procedure
or technique, it must meet the Frye standard by establishing
that the technique and the principles behind it are generally
accepted in the relevant scientific community.
To meet the Frye standard, the scientific theories and
techniques must be generally accepted in the specific scientific
community or field to which they belong. In determining the
appropriate or relevant scientific community, courts will
generally not consider the entire spectrum of scientists. They
will instead only consider those scientists ``whose scientific
background and training are sufficient to allow them to
comprehend and understand the [involved scientific] process and
form a judgment about it.'' (12) The scientists will most often be
limited to those who have had direct experience with the
questioned scientific procedure, (13) or at least scientists who
``would be expected to be familiar with its use.'' (14)
Once the appropriate scientific community is determined,
the court must also decide if the questioned procedure,
technique, and principles are generally accepted within that
community. The Frye decision, as well as most of the decisions
of other Federal and State courts that have adopted the Frye
standard, give little if any guidance as to what is sufficient
general acceptance. Those courts generally