                  IN THE SUPREME COURT OF TENNESSEE

                            AT NASHVILLE

                         (HEARD AT JACKSON)
                                                       FILED
                                                        November 3, 1997

                                                      Cecil W. Crowson
                                    )      FOR PUBLICATION
STATE OF TENNESSEE                  )                Appellate Court Clerk
                                    )      FILED:   NOVEMBER 3, 1997
           Appellee                 )
                                    )      DAVIDSON COUNTY
V.                                  )
                                    )      HON. J. RANDALL WYATT, JR.,
BOBBY ED BEGLEY                     )          JUDGE
                                    )
           Appellant                )      NO. 01-S-01-9607-CR-00134




For Appellant:                      For Appellee:

JEFFREY A. DEVASHER                 JOHN KNOX WALKUP
Nashville, TN                       Attorney General and Reporter

                                    MICHAEL E. MOORE
                                    Solicitor General

                                    KATHY A. MORANTE
                                    Deputy Attorney General
                                    Nashville, TN

                                    VICTOR S. JOHNSON, III
                                    District Attorney General

                                    KATIE MILLER
                                    Assistant District Attorney
                                     General
                                    Nashville, TN




                               OPINION




AFFIRMED                                                     BIRCH, J.
              We granted the defendant’s application for permission to

appeal in order to determine whether the trial court abused its

discretion1 in admitting testimony concerning the results of a

certain method of DNA analysis. While we have previously considered

the admission of the results of DNA analysis using the “restriction

fragment length polymorphism” (RFLP) method, we address for the

first time the admission of testimony regarding DNA analysis using

the   “polymerase    chain   reaction”     (PCR)   method.   PCR   is   to   be

distinguished from RFLP, the method more statistically precise and

firmly established in both the scientific and legal community.

After a jury-out hearing, the trial court admitted expert testimony

about the results of the PCR analysis performed on the defendant’s

clothing, and the Court of Criminal Appeals upheld the trial court’s

determination.



              For the reasons stated, we conclude that the PCR method of

DNA analysis is a “DNA analysis” within the definition of Tenn. Code

Ann. § 24-7-117(a) (Supp. 1991)2 and is therefore exempt from a


      1
      Abuse of discretion is the standard for review of a trial
court’s admission of scientific evidence. State v. Ballard, 855
S.W.2d 557, 562 (Tenn. 1993).
      2
          Section 24-7-117 provides:

           (a) As used in this section, unless the context
      otherwise requires, “DNA analysis” means the process
      through which deoxyribonucleic acid (DNA) in a human
      biological specimen is analyzed and compared with DNA from
      another biological specimen for identification purposes.

           (b)(1) In any civil or criminal trial, hearing or
      proceeding, the results of DNA analysis, as defined in
      subsection (a), are admissible in evidence without
      antecedent expert testimony that DNA analysis provides a
      trustworthy   and   reliable   method   of   identifying
      characteristics in an individual's genetic material upon
      a showing that the offered testimony meets the standards

                                       2
judicial determination of reliability and trustworthiness, as would

normally be required under Tenn. R. Evid. 703.3                 Furthermore, the

expert     testimony    adduced     at   trial      satisfied    the    relevancy

requirements     of    Tenn.   R.   Evid.    4014   and   was    of    substantial

assistance to the trier of fact as required by Tenn. R. Evid. 702.5



     of admissibility set forth in the Tennessee Rules of
     Evidence.

          (2) Nothing in this section shall be construed as
     prohibiting any party in a civil or criminal trial from
     offering proof that DNA analysis does not provide a
     trustworthy   and   reliable   method   of   identifying
     characteristics in an individual's genetic material, nor
     shall it prohibit a party from cross-examining the other
     party's expert as to the lack of trustworthiness and
     reliability of such analysis.

          (c) In any civil or criminal trial, hearing or
     proceeding, statistical population frequency evidence,
     based on genetic or blood test results, is admissible in
     evidence to demonstrate the fraction of the population
     that would have the same combination of genetic markers as
     was found in a specific biological specimen. For purposes
     of this subsection, “genetic marker” means the various
     blood types or DNA types that an individual may possess.

     3
         Rule 703 states:

          The facts or data in the particular case upon which
     an expert bases an opinion or inference may be those
     perceived by or made known to the expert at or before the
     hearing. If of a type reasonably relied upon by experts
     in the particular field in forming opinions or inferences
     upon the subject, the facts or data need not be admissible
     in evidence. The court shall disallow testimony in the
     form of an opinion or inference if the underlying facts or
     data indicate lack of trustworthiness.
     4
         Rule 401 states:

          “Relevant evidence” means evidence having any
     tendency to make the existence of any fact that is of
     consequence to the determination of the action more
     probable or less probable than it would be without the
     evidence.

     5
         Rule 702 states:


                                         3
Therefore, the results of the PCR analysis in this case were

properly admitted, and the defendant's convictions and sentences are

affirmed.



            Because the defendant does not contest the sufficiency of

the convicting evidence,6 a brief summary of the facts is sufficient

to place the issue into context.



            The record reveals that the defendant, Bobby Ed Begley,

lived in the house next to the house of Delma Johnson, age 72.    They

were acquainted with each other; Begley had been to Johnson’s house

on several prior occasions to use Johnson’s telephone.   On February

5, 1993, Begley went to Johnson’s house and asked to borrow $10;

Johnson handed the $10 to him.     When Begley offered to return the

$10 later that evening, Johnson admonished him repeatedly that he

should not do so.



            In spite of the admonishments, Begley returned later that

evening.    As soon as Johnson opened the door, Begley rushed in past



          If scientific, technical, or other specialized
     knowledge will substantially assist the trier of fact to
     understand the evidence or to determine a fact in issue,
     a witness qualified as an expert by knowledge, skill,
     experience, training, or education may testify in the form
     of an opinion or otherwise.

     6
      After this application was granted the defendant asked the
Court to consider whether counts three through eight of the
indictment, under which he was convicted of aggravated rape, were
fatally deficient by their failure to allege the requisite mens rea
element of aggravated rape. Consistent with our decision in State
v. Hill, No. 01-S-01-9701-CC-00005 (Tenn. filed Nov. 3, 1997), we
find that the failure of the indictments in this case to allege a
specific mens rea does not affect the validity of the defendant’s
convictions. We decline to address this issue further.

                                   4
her.   He beat and battered her severely.        He sexually penetrated her

several times.       He then stuffed her into the trunk of her car,

closed the trunk, and drove off.



            He drove a short distance and stopped.           He pulled Johnson

out of the trunk and dumped her in some bushes.               The temperature

was below freezing that night, and Johnson was wearing only a

nightgown and robe.



            Approximately two to three hours passed before Johnson was

discovered and rescued.          She was in poor condition and weak from

loss of blood.       However, at the hospital she was able to identify

Begley as her assailant, and she identified him again at trial.



            Arresting officers observed what appeared to be blood on

Begley’s trousers.      The trousers were seized, and the blood spots

were subjected to DNA analysis at a biomedical laboratory in North

Carolina.



            Following a jury trial, the defendant was convicted of

especially aggravated kidnaping, attempted first-degree murder,

aggravated robbery, and several counts of aggravated rape.



                                         I



            A brief and simplified explanation of the theory and

methods   of   DNA    analysis    will   be   helpful   at   the   outset.   The




                                         5
Washington Supreme Court gave the following general explanation

about the nature of DNA:


                    DNA (deoxyribonucleic acid) is the
                    chemical material contained within an
                    organism's cells which determine[s]
                    that organism's physical composition.
                    Human    cells   each    contain    46
                    chromosomes, which are arranged in 23
                    pairs. One chromosome in each pair
                    is   inherited   from  each    parent.
                    Approximately   100,000    genes   are
                    located on the chromosomes. Genes,
                    which consist of DNA, determine eye,
                    hair,     and   skin    color,     the
                    organization of body parts, and
                    virtually everything else about our
                    physical state.     Each individual,
                    with the exception of identical
                    twins, has a unique DNA structure
                    which is contained in every nucleated
                    cell. That structure remains constant
                    throughout a human lifetime. It can
                    be found in blood, semen, hair, bone
                    marrow, and other tissues.


State      v.   Cauthron,     846   P.2d   502,   508   (Wash.     1993)    (footnote

omitted).         The   DNA    analysis    at   issue   in    this   case    is   more

specifically known as DNA typing.               Ninety-nine percent of the DNA

molecule is the same for every individual.7                  Polymorphisms are the

DNA segments which exhibit genetic variation within the population.

These variations provide the basis for DNA typing.                   DNA typing is

used       to   determine     whether   biological      material     from    a    known

individual can be linked to a sample from an unidentified specimen.




       7
      Only three million of the three billion-odd base pairs of the
DNA molecule differ from one individual to the next.        National
Research Council, The Evaluation of Forensic DNA Evidence 63 (1996).

                                           6
             Forensic     applications       of   DNA      typing     involve    two

components:       molecular biology and population genetics.              Molecular

biological techniques, such as the RFLP and PCR methods, permit

scientists to extract and examine unidentified DNA from a given

piece of evidence.          In the PCR method, the sample of DNA is

subjected    to    an   enzyme   and   heating    treatment,      which   causes   a

specific segment of the DNA to be “amplified” by billions of

replications. To determine whether two samples could have come from

the same person, the samples are compared to see if they produced

the same pattern.       Thomas M. Fleming, Annotation, Admissibility of

DNA Identification Evidence, 84 A.L.R.4th 313, 323 (1991).                   In the

RFLP   method,     an   enzyme   treatment    cuts   the    DNA     molecules   into

fragments.     The resulting length and location of these fragments

differ among individuals; samples are then compared to see if they

match.   Id. at 320.



             Population genetics is then used to determine the degree

to which two samples are similar by greater than a random chance.

The Alaska Court of Appeals explained:


                         Theoretically, each person's DNA
                    is   unique;   that   is,   with  the
                    exception of “identical twins,” no
                    two persons share exactly the same
                    complement of genes.      At the same
                    time, however, it is rare for a
                    specific gene to be unique to a
                    single individual.    Some genes--for
                    instance, the genes that direct our
                    bodies to form two arms and two
                    legs--are found in virtually every
                    human being.    Other genes, such as
                    those that determine skin, hair, and
                    eye color, are shared by substantial
                    numbers of people. Still other genes
                    are so rare that they are shared by


                                         7
                only small percentages of the general
                population. . . .

                     That genes8 are shared by groups
                of people is of crucial significance
                when DNA testing is employed to
                identify the perpetrator of a crime.
                Even   though    DNA    testing   can
                accurately identify a person's genes,
                the fact that a person carries a
                particular gene means little unless
                scientists can also tell us the
                likelihood that other people share
                that same gene.     The fact that a
                defendant carries the same gene as
                was found in a tissue sample taken at
                the scene of the crime is not
                particularly probative if a high
                percentage of the population also
                carry that same gene; conversely, if
                the gene is quite rare, then the DNA
                match becomes correspondingly more
                probative.


Harmon v. State, 908 P.2d 434, 440-41 (Alaska Ct. App. 1995)

(footnote omitted).



          Both the RFLP method and the PCR method have advantages

and disadvantages.     The most significant advantage of the RFLP

method is its specificity.       Through application of statistical

population frequency evidence to the test results, the RFLP method

narrows   the   possible   contributors   of   a   given   sample   to   an

infinitesimally small portion of the population, and in doing so

informs the jury of the likelihood the sample was contributed by

someone other than the defendant.         On the other hand, the RFLP


     8
      Although the Alaska Court of Appeals used the term “genes”
when explaining the DNA testing process, they recognized that it is
actually certain alternative forms of a particular gene, known as
“alleles,” which are copied and compared in this process.
Technically, it is the frequency with which these alleles occur in
a given population which is examined to exclude or not exclude a
certain suspect as the source of the unknown DNA. The court used
the term “genes” for the sake of simplicity.

                                   8
method is time-consuming and requires a large quantity of high-

quality genetic material--at least a quarter-sized stain of blood or

a dime-sized stain of semen is required to perform the RFLP method

of DNA analysis.     Also, unless the samples are recovered when

relatively fresh, they degrade into fragments too small for the RFLP

method.



           In contrast, the PCR method can be performed with very

small amounts of genetic material, since the process itself allows

amplification to produce an amount suitable for testing.         The

process is relatively simple and can yield results in as little as

twenty-four hours.   The PCR method, however, is less statistically

precise.   Further, if the PCR method is not carefully performed, it

is more susceptible to contamination than the RFLP method.   See id.

at 440; George Bundy Smith & Janet A. Gordon, The Admission of DNA

Evidence in State & Federal Courts, 65 Fordham L. Rev. 2465, 2471-72

(May 1997); Thomas M. Fleming, Annotation, Admissibility of DNA

Identification Evidence, 84 A.L.R.4th 313, 320-25 (1991).



                                 II



           The admission of expert testimony regarding scientific and

technical evidence is governed by Tenn. R. Evid. 702 and 703.

McDaniel v. CSX Transportation, Inc., No. 01-S-01-9605-CV-00095

(Tenn. Sept. 29, 1997).9    Questions regarding the admissibility,


     9
      McDaniel held that the pre-Rules of Evidence test of Frye v.
United States, 293 F. 1013 (D.C. Cir. 1923), which required that
scientific evidence be generally accepted in the particular field to
which it belonged in order for it to be admissible, was superseded
by the adoption of Tennessee Rules of Evidence 702 and 703.

                                  9
qualifications, relevancy and competency of expert testimony are

left to the discretion of the trial court, whose ruling will not be

overturned    in    the   absence    of    abuse       or   arbitrary     exercise    of

discretion.        Ballard,   855    S.W.2d       at    562.      In     McDaniel,    we

promulgated    the    principles     for    the     trial      court’s    guidance    in

deciding whether to admit scientific or technical evidence.



             First, the evidence must be relevant to a fact at issue in

the case.     Tenn. R. Evid. 401, 402.              Second, the expert must be

qualified by specialized knowledge, skill, experience, training, or

education in the field of expertise, and the testimony in question

must substantially assist the trier of fact to understand the

evidence or determine a fact in issue.                       Tenn. R. Evid. 702;

McDaniel, slip op. at 14; see also Otis v. Cambridge Mutual Fire

Ins. Co., 850 S.W.2d 439, 443 (Tenn. 1992).                      Finally, when the

expert   witness     offers   an    opinion    or      states    an    inference,    the

underlying facts or data upon which the expert relied must be

trustworthy.       Tenn. R. Evid. 703; McDaniel, slip op. at 14.



             Simply put, scientific or technical evidence will not be

admissible unless it is determined to be reliable.                    The reliability

of scientific evidence is determined by considering the following

nonexclusive list of factors:


                         1.   Whether  the   scientific
                    evidence has been tested and the
                    methodology with which it has been
                    tested;




McDaniel, slip op. at 16.

                                          10
                        2.   Whether the evidence has
                   been subjected to peer review or
                   publication;

                        3.   Whether a potential rate of
                   error is known;

                        4.   Whether,    as    formerly
                   required by Frye, the evidence is
                   generally accepted in the scientific
                   community; and

                        5.   Whether    the    expert’s
                   research in the field has been
                   conducted independent of litigation.


McDaniel,    slip     op.    at    11      (citing    Daubert     v.   Merrell    Dow

Pharmaceuticals, 509 U.S. 579, 593-94, 113 S.Ct. 2786, 2796-98, 125

L.Ed.2d     469,    482-83        (1993)       and   Daubert     v.    Merrell     Dow

Pharmaceuticals, Inc., 43 F.3d 1311, 1317 (9th Cir.)(“Daubert II”),

cert. denied, 116 S.Ct. 189 (1995)).



                                           III



            Richard    Guerrieri,          a    forensic   scientist    with     Roche

Biomedical Laboratories, testified as a State’s witness regarding

the results of the PCR analysis.                     During a jury-out hearing,

Guerrieri testified that he had a Master of Science degree in

Forensic Chemistry and a Bachelor of Science degree in Biology, with

course work equivalent to a similar degree in Chemistry.                       He had

worked in the field of forensic science for fifteen years, with the

most recent six years devoted to DNA analysis.                 During that time, he

had worked hundreds of cases with thousands of samples.                        He had

testified as an expert in forensic science between eighty and ninety

times and as an expert in DNA analysis approximately thirty of those

times.    He had only testified on one prior occasion regarding DNA

                                           11
analysis using the PCR method.           The rest of his experience in

testifying about DNA was in cases where the RFLP method was used.



            Despite his limited experience in testifying on the PCR

method of DNA analysis, he testified that it was recognized and

accepted in the scientific community and had been admitted into

evidence in twenty to thirty states.10             He was aware of many

publications that had discussed the validity of the PCR method.

Guerrieri admitted that no DNA analysis can establish identity to an

absolute certainty.    The available methods are tests of exclusion;

they are designed to determine whether a person can be excluded as

the source of the unidentified evidence.



            The trial court found Guerrieri qualified as an expert and

ruled that he could testify regarding the results of the PCR

analysis.    Guerrieri then testified that the victim’s DNA is type

“1.2, 1.2,” a type shared by 6.5% of the black population.                The

defendant’s DNA is type “4, 4,” a type shared by 9.8% of the black

population.11



            Guerrieri further testified that the PCR analysis of spots

on the defendant’s clothing resulted in the detection of a mixture

of type 1.2 and type 4 DNA.      Because of the differing intensity of

the two types found on the defendant’s clothing, Guerrieri opined


     10
      Guerrieri also testified that based on his communications with
FBI personnel, he was under the impression that the PCR method had
been admitted in Tennessee courts. However, this Court is not aware
of any appellate cases in Tennessee addressing this issue.
     11
      Apparently    both   the   defendant   and   the   victim   are   black
Americans.

                                    12
that they most likely originated from two different persons, a “1.2,

1.2” type and a “4, 4” type.                       Nevertheless, 18% of the black

population do have the combination “1.2, 4” type of DNA.



                                              IV



            The Legislature has determined that DNA analysis is a

trustworthy and reliable method of identifying characteristics in an

individual's genetic material and will be admissible so long as it

otherwise meets the requirements of the Tennessee Rules of Evidence.

Tenn. Code Ann. § 24-7-117(b)(1) (Supp. 1991).                            The Legislature

evidently enacted this statute in order to ease the admission of DNA

evidence in Tennessee.            Neil P. Cohen, et al., Tennessee Law of

Evidence § 401.34, at 147 (3d ed. 1995).                     Even before Tenn. Code

Ann.   §   24-7-117      was    enacted,       Tennessee     courts       recognized      the

reliability and trustworthiness of DNA evidence.                            See State v.

Harris,    866    S.W.2d       583,    587    (Tenn.      Crim.    App.    1992)   (Harris

violation    occurred      in    1989,       before    the   effective      date    of   the

statute).



            Tennessee      Code        Annotated      §   24-7-117(a)       defines      “DNA

analysis”    as    the    process       of    analyzing      and   comparing       DNA    for

identification purposes.              The defendant asserts that the PCR method

of DNA analysis is a method of exclusion, not identification, and as

such is not governed by Tenn. Code Ann. § 24-7-117.                         Additionally,

the defendant claims the PCR method’s reliability has not been

adequately established.               We find this argument without merit.                 At

the time the statute was passed, the DNA “method of choice” was the


                                              13
RFLP method, which, like the PCR method, is not definitive in

identifying a particular person.        Nevertheless, the RFLP method has

clearly   been     considered   by    the    courts   to    be    a    method     of

identification.      See, e.g., State v. Edwards, 868 S.W.2d 682, 697

(Tenn. Crim. App. 1993); Harris, 866 S.W.2d at 386; State v.

Gregory, 862 S.W.2d 574, 576 (Tenn. Crim. App. 1993).             While the PCR

and RFLP methods of DNA analysis can be characterized as tests of

exclusion, there are nevertheless relevant to the identification of

the perpetrator of a crime.       Because the results of the PCR method

of DNA analysis are relevant to identification, the PCR method falls

under the § 24-7-117(a) definition of “DNA analysis.”



           Under    the    McDaniel   analysis   of   the   admissibility        of

scientific evidence, the initial question is whether the results of

the PCR analysis are relevant under Tenn. R. Evid. 401.               We conclude

that they are.      The discovery of DNA consistent with the victim’s

DNA, but inconsistent with the defendant’s DNA, on the defendant’s

clothing is relevant because it tends to identify the defendant as

the assailant.      The results of the PCR method of DNA analysis may

not be as probative as that of the RFLP method, because the PCR

method results in a large pool of possible DNA contributors, instead

of the infinitesimally small number resulting from the RFLP method.

Under the results of the PCR analysis here, 6.5% of the entire black

population   have    the   victim’s    DNA   type,    and   18%   of    the     same

population have a combination of the victim’s and defendant’s DNA

type.   Yet, the PCR method of DNA analysis, while not as specific as

the RFLP method, serves by process of elimination to increase the

probability of an identification and thus is relevant.


                                      14
            The next question under the McDaniel analysis is whether

the   witness    was     qualified    as   an   expert   by   knowledge,   skill,

experience,      training,    or     education    and    whether   the   witness’

specialized knowledge substantially assisted the trier of fact to

understand the evidence or to determine a fact in issue.                 Tenn. R.

Evid.   702.       The    expert     witness,    Guerrieri,    was   extensively

qualified, by both education and experience, in the field of DNA

testing.    Furthermore, Guerrieri substantially assisted the jury to

properly understand the complex DNA evidence.              He clearly explained

the process and results of the PCR analysis, without overstating the

conclusiveness of the evidence.             We conclude that the requirements

of Rule 702 are satisfied.



            Next, under McDaniel and Tenn. R. Evid. 703 the facts or

data relied upon by an expert in giving his or her opinion must be

trustworthy and reliable. Because the DNA evidence at issue here is

governed by Tenn. Code Ann. § 24-7-117, the evidence is statutorily

regarded as trustworthy and reliable.             Tennessee Code Annotated §

24-7-117 exempts DNA evidence from the trial court determination

under Rule 703 of whether it provides a trustworthy and reliable

method of identifying characteristics in an individual’s genetic

material.   Consequently, a judicial determination of the scientific

reliability of the evidence is unnecessary.



            Nevertheless, this Court finds the PCR method of DNA

analysis    an    inherently       trustworthy     and    reliable   method    of

identification.        In doing so, we join a number of other state and

federal jurisdictions that have already recognized the reliability


                                           15
and admissibility of evidence based on the PCR method.12             Several

factors support our finding.       First, the PCR method of DNA analysis

has   been    subjected   to   extensive   peer   review.   One    court   has

estimated that over four thousand published scientific articles

exist addressing the merits of the method.         State v. Lyons, 924 P.2d

at 813.      Second, the PCR method is considered reliable and error-

free, as long as protocols and controls are utilized.             Id. at 812.

With respect to acceptance of the PCR method by the scientific

community:


                  In  1992,   the  National   Research
                  Council noted that “[t]he theory of
                  PCR analysis . . . is scientifically
                  accepted and has been accepted by a
                  number of courts.”     In 1996, the
                  National Research Council reported


      12
      See United States v. Hicks, 103 F.3d 837 (9th Cir. 1996),
cert. denied 117 S.Ct. 1483 (1997); United States v. Beasley, 102
F.3d 1440 (8th Cir. 1996), cert. denied 117 S.Ct. 1856 (1997);
United States v. Shea, 957 F.Supp. 331 (D.N.H. 1997); United States
v. Lowe, 954 F.Supp. 401 (D. Mass. 1996); Williams v. American
Cyanamid, 164 F.R.D. 608 (D.N.J. 1995), aff’d, 164 F.R.D. 615
(D.N.J. 1996); United States v. Yee, 134 F.R.D. 161 (N.D. Ohio
1991), aff’d sub nom. United States v. Bonds, 12 F.3d 540 (6th Cir.
1993); Seritt v. State, 647 So.2d 1 (Ala. Crim. App. 1994), cert.
denied (Ala. 1994); Harmon v. State, 908 P.2d 434 (Alaska Ct. App.
1995); People v. Morganti, 43 Cal. App. 4th 643, 50 Cal. Rptr.2d 837
(1996), review denied (Cal. 1996); Redding v. State, 464 S.E.2d 824
(Ga. Ct. App. 1995); People v. Pope, 672 N.E.2d 1321 (Ill. App. Ct.
1996), appeal denied (Ill. 1997); State v. Hill, 895 P.2d 1238 (Kan.
1995); State v. Spencer, 663 So.2d 271 (La. Ct. App. 1995);
Commonwealth v. Vao Sok, 425 Mass. 787, ___ N.E.2d ___ (1997); State
v. Brown, 949 S.W.2d 639 (Mo. Ct. App. 1997); State v. Moore, 885
P.2d 457 (Mont. 1994), overruled on other grounds in State v.
Gollehon, 906 P.2d 697 (Mont. 1995); State v. Harvey, 1997 WL
422956, ___ A.2d ___ (N.J. 1997); People v. Morales, 227 A.D.2d 648,
643 N.Y.S.2d 217 (1996), appeal denied (N.Y. 1996); State v. Lyons,
924 P.2d 802 (Or. 1996); State v. Moeller, 548 N.W.2d 465 (S.D.
1996); Campbell v. State 910 S.W.2d 475 (Tex. Crim. App. 1995),
cert. denied 116 S.Ct. 1430 (1996); Spencer v. Commonwealth, 393
S.E.2d 609 (Va.), cert. denied 498 U.S. 908 (1990); State v.
Russell, 882 P.2d 747 (Wash. 1994), cert. denied 514 U.S. 1129
(1995). But see State v. Bible, 858 P.2d 1152 (Ariz. 1993), cert.
denied 511 U.S. 1046 (1994); State v. Carter, 524 N.W.2d 763 (Neb.
1994)(holding such evidence inadmissible).

                                      16
                  that   “[t]he   technology  for DNA
                  profiling   and    the  methods for
                  estimating frequencies and related
                  statistics have progressed to the
                  point where the reliability and
                  validity of properly collected and
                  analyzed DNA data should not be in
                  doubt.”


Id. at 812, n.22 (citations omitted).                    Thus, the PCR method is

generally accepted in the scientific community as a valid means for

identifying    unknown     contributors       of    body    tissue/fluid      samples.

Finally, Guerrieri testified that he spent extensive time developing

and validating DNA testing methods, independent of any litigation.



          Hereafter,       the   PCR     method     of     DNA   analysis   shall    be

admissible into evidence without antecedent expert testimony as to

its trustworthiness and reliability, pursuant to Tenn. Code Ann. §

24-7-117(b)(1).       As     provided      by      that     statute,   parties      are

nevertheless    allowed     to   offer    proof     that     DNA   analysis    is   not

trustworthy and reliable.         Tenn. Code Ann. § 24-7-117(b)(2).                 For

example, a party can challenge the reliability of a particular test

in any given case by a showing of sloppy handling of samples,

failure to train the personnel performing the testing, failure to

follow protocol, and the like.13          Such a challenge, however, will go

to the weight, not the admissibility, of DNA evidence.



          We hold that the trial court's admission of the evidence

related to the Polymerase Chain Reactive method of DNA analysis was

not an abuse of discretion.        Accordingly, the judgment of the Court



     13
      The defendant did not raise any issue concerning the manner
in which the specimen was handled or the test performed.

                                         17
of Criminal Appeals is affirmed.    Costs of this cause are taxed to

Begley for which execution may issue if necessary.




                              _______________________________
                              ADOLPHO A. BIRCH, JR., Justice

CONCUR:

Anderson, C.J.
Drowota, Reid, Holder, JJ.




                               18
