Quality assurance

1
Quality assurance
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Certification and Accreditation
Formal external review of both a forensic
laboratory and the individuals performing work in
that venue is useful for a number of
reasons. Internally, the results provide the
laboratory and its personnel with valuable
information that can be used to detect and
correct deficiencies and improve
performance. The intent of impartial assessment
provides judicial officers, the court, and other
interested parties with information regarding the
laboratorys credibility and fitness to reliable
and accurately perform forensic testing.
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Certification
In the United States, certification is not
currently required to perform forensic testing,
but is regarded as highly favorable. The trend is
toward encouraging certification in a least an
analysts field of specialization.
Certification examinations are provided by the
American Board of Criminalistics (ABC), a group
governed by a rotating quorum of qualified
workers in the field who have an interest in
upholding a self-imposed standard within their
own ranks. Written examinations are offered in
both general knowledge of forensic science, as
well as in the various specialties. A Technical
Specialist examination in DNA has recently been
introduced by the ABC.
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Accreditation
Accreditation pertains to the qualification of a
laboratory that provides forensic testing
services. This service, provided by the American
Society of Crime Laboratory Directors (ASCLD), is
also at present voluntary and self-regulated.
Accreditation is also offered by the National
Forensic Science and Technology Centre (NFSTC).
Similar to individual certification, an
inspection serves to identify criteria that can
be used by a laboratory to assess its level of
performance and improve its operations. It is
also an impartial means by which those that
depend on the laboratorys services, as well as
the general public, can ascertain that a
particular lab meets established standards.
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To qualify for accreditation, a laboratory must
demonstrate that it meets the standards for
management, operations, personnel, procedures,
equipment, security, and health and safety
procedures. The laboratory analysts must also
participate in regular proficiency testing
procedures. Accreditation is granted for 5
years, provided that a laboratory continues to
meet the standard during this period. Both the
initial accreditation and re-accreditation on a
5-year cycle require a full review of the
laboratory, including an onsite inspection. To
remain in compliance, the laboratory must also
conduct an internal audit every year and
requisition and external audit on alternate years
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SWDGAM (Formerly TWGDAM)
TWGDAM, the Technical Working Group on DNA
Analysis Methods, was originally formed in 1988
at the behest of the FBI. Its self-assigned
functions were to provide a forum for forensic
DNA laboratories to discuss issues, conduct
studies, and reach a consensus as to the DNA
methodologies to be used in North American crime
laboratories. In 1999, the name was changed to
the Scientific Working Group on DNA Analysis
Methods (SWGDAM). SWGDAM provides a medium for
the different laboratories throughout the country
to exchange DNA testing data, and has played a
particularly important role in establishing
guidelines for working forensic DNA laboratories.
Members of SWGDAM include forensic scientists
from public laboratories throughout the United
States.
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The group has established and continues to update
guidelines for quality assurance, proficiency
testing, and interpretation, and has also
sponsored several inter-laboratory
studies. SWGDAM has also issued several
consensus statements regarding the validity and
reliability of various DNA techniques and
calculations, including the ill-fated ceiling
calculation, guidelines for statistical treatment
of forensic DNA data, and responses to DNA
testing challenges. Although criticized by some
as being too exclusive, particularly in the early
stages of decision-making, and also as
potentially biased in developing standards in
which it has a vested interest, SWGDAM has
nevertheless emerged as a nucleus around which
the forensic community can assemble as the DNA
typing explosion continues.
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Impact of DNA typing
The use of DNA typing is not confined to those
cases in which body fluids, hairs or tissue are
left at the crime scene or on the victim by the
perpetrator, thereby connecting a suspect to the
scene or victim. Just as common is the situation
where evidence is left by a victim on the suspect
or the suspects belongings, which will establish
previous contact between the accused and the
victim. In circumstances where several crimes
exhibiting a common pattern are committed, DNA
analysis may indicate whether the crimes are
serial in nature, committed by a single
individual, or whether different persons are
responsible. If a string of serial crimes is
identifies, it may be possible to eliminate some
of the crimes as the work, for example, of
copycat criminals.
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The collateral benefits of DNA analysis for the
criminal justice system are also impressive. The
likelihood that defendants will enter pleas of
guilty when faced with DNA test results should
increase. It has been reported that most rape
defendants confronted with DNA test results
implicating them have pled guilty. This
encouraging trend should also be seen in
connection with other crimes, except when the
stakes are a matter of life and death for the
defendant. As a corollary to the increase in
guilty pleas because of overwhelming DNA
evidence, victims may be more willing to report
rapes to police. One deterrent to reporting is
the additional trauma incurred by victims while
testifying at a trial. The increased likelihood
of guilty pleas generated by the DNA analysis may
diminish that deterrent. Moreover, reports have
indicated that rape victims are more likely to
file a complaint if there is a high probability
of conviction and they are less likely to make a
report when the probability is low. DNA testing
should increase dramatically the convictions in
non-acquaintance rape cases.
10
That DNA typing has been favorable recognized in
the scientific and legal literature is an
understatement. All of the journal articles,
save a couple, have proclaimed DNAs theory and
technique as accepted by the scientific
community. However, if the theory, technique,
procedure, and legal process are not also
accepted by the courts, DNA will not be
admissible as evidence, despite the acceptance of
DNA testing among molecular biologist,
geneticists, and other applicable scientific
disciplines. When all is said and done, its
admission into evidence rest solely upon
principles of law.
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The legal standards for admissibility of DNA
typing
Although the theory underlying DNA typing is
neither controversial nor of recent vintage, its
application to forensic identification in legal
proceedings, particularly in the criminal justice
system, is new. To the extent that the theory
and technique have not been judicially sanctioned
in a forensic setting, DNA typing is novel
scientific evidence. As such, the proponents of
DNA typing, upon its debut in each jurisdiction,
will, prior to its judicial acceptance, have to
satisfy the test for admissibility prevailing in
the particular jurisdiction in which the evidence
is to be offered. Once the test has been met,
any proponent of similar evidence thereafter
will be relieved of the burden of repeatedly
showing that DNA typing passes the
jurisdictions test for admissibility.
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There are two primary tests used by the courts
for determining the admissibility of novel
scientific evidence The Frye test and the
relevancy test. A number of jurisdictions,
however, apply a variation of the judicial themes
represented by those tests. The ultimate
objective of the Frye test is to ensure that only
scientific evidence that is reliable will be
admitted. It does so by requiring that the
underlying theory and technique have been
sufficiently used and tested within the
scientific community to have gained general
acceptance.
13
Obtaining known and unknown biological samples
The prosecution must satisfy the court that the
physical evidence upon which the testing was
conducted was obtained in accord with the Fourth
Amendment to the constitution, which proscribes
unreasonable searches and seizures. Collecting
forensic evidence such as blood, hair, saliva,
skin, or semen from a victim or a crime scene
usually will not involve Fourth Amendment issues
because the defendant will be unlikely to have a
reasonable expectation of privacy in the object
or place from which the specimens are
seized. Collection known samples from the
defendant, however, may involve Fourth Amendment
rights. Prior to arrest, samples may be collected
from a suspect pursuant to a search warrant,
based upon probable cause and issued by a
magistrate. Post arrest, the prosecution may
obtain either a warrant or a court order
directing that the defendant submit to the taking
of biological samples.
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Refusal by the defendant to submit to a
collection of specimens may be admissible at
trial as circumstantial evidence of guilt. The
more difficult situation arises when the police
have no particular individual they suspect as the
perpetrator of the crime they are investigating,
or when they have a suspect but lack sufficient
evidence to establish probable cause for a search
warrant. The police must then resort to methods
justifiable on a standard of proof less than that
which has traditionally been required for a
search warrant.
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Chain of custody
Before an expert will be allowed to testify at a
trial as to the results of the DNA analysis -
must establish a proper chain of custody for the
substances subjected to the analysis. The chain
of custody requirement has two objectives. The
first is to lay a proper foundation connecting
the evidence to the defendant or to a place or
object that is relevant to the case. This is a
form of authentication that establishes the
relevance of the evidence, one of the
prerequisites to admissibility. The second
purpose of a chain of custody for physical
evidence is to ensure that the object is what its
proponent claims it to be. This is accomplished
by ruling out any tampering with, and substantial
alteration or substitution of, the evidence. If
the substance analyzed for the presence of DNA
has been tampered with or altered in a
significant way, it becomes, in effect a
substance different from the one originally
seized, and its relevance to the case disappears.
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Alterations performed as a result of testing the
substance, of course, do not affect the chain of
custody. In most cases, the critical links in
the chain of custody are those from the time the
evidence was obtained to the time it was
scientifically analyzed, since the latter is the
time at which the integrity of the evidence is of
paramount importance. Similarly, if another
substance is substituted for that which was
originally obtained, the evidence is no longer
authentic and cannot be admitted into evidence.
By showing the proper custody of the evidence,
any question of substitution, alteration, or
tampering can be dispelled. Particularly with
DNA typing, a proper chain of custody is required
because the substances analyzed are not
identifiable in a singular sense.
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Failure to adequately prove the chain of custody
of the substance subjected to DNA testing will
undoubtedly cause the exclusion of the evidence.
Once this factual predicate cannot be met, the
experts testimony becomes irrelevant and
consequently inadmissible. The party offering
the evidence shoulders the burden of proving the
chain of custody. Once a showing has been made
to a reasonable certainty, even though there may
be some weak links, the burden shift to the
opponent to establish that the chain has been
broken.
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Proper laboratory procedures
The proper application of the technique by the
laboratory with respect to the particular
evidence being offered and the qualifications of
the experts are issues that should be raised by
the opposing counsel whenever scientific
evidence is to be introduced. If the technique
is not properly applied by qualified experts, or
if laboratory procedures and protocols are not
followed the quality control devices ignored or
compromised, the reliability of the test results
is diminished or destroyed, and relevance is
lost. The degree to which there is deviation
from appropriate laboratory procedures,
protocols, and quality controls normally goes to
the weight given the experts testimony by the
trier of fact.
19

• Nicole Brown Ronald Goldman stabbed to death
  June 1994 outside her home in Brentwood,
  California.
• O.J. Simpson charged with the murders.
• DNA evidence
• Drops of blood leading away from crime scene
  13 loci matched O.J.
• Blood on glove found at O.J.s home 8 loci
  matched Nicole and 10 loci matched Ronald.
• Blood from socks found at O.Js home 21 loci
  (1 in 9.7 billion)
• Why had the jury acquitted O.J. Simpson on
• two counts of first-degree murder on October 3,
  1995?

20
Police did not wear protective clothing at the
crime scene. Photographs showed detective
walking through bloodstains, leaving bloody shoe
prints throughout the crime scene as well as
outside. Detectives who did not wear protective
clothing traveled from the crime scene to O.J.
Simpsons residence and potentially could have
transferred forensic evidence from one location
to another. Did not change gloves between
handling different samples. Did not adequately
document the blood testing. Failed to follow
rules that would ensure against contaminating
blood samples. Blood taken from O.J. Simpson was
spilled onto plastic gloves and may have
contaminated evidence material.
21
Setting standards for DNA practice in South Africa
The Forensic Science Laboratory (FSL) of the SAPS
was established on 15 January 1971. In addition
to the main laboratory in Pretoria, decentralised
offices have been established in Cape Town, Port
Elizabeth and Durban. The Biology Unit is
responsible for the analyses of evidentiary
material of biological origin, (e.g. body fluids,
human tissue and hair) with the aim of
accomplishing the highest possible degree of
human identification through forensic DNA
analysis and microscopical comparison (the latter
exclusively on hair). In June 1996, Perkin
Elmer Applied Biosystems sponsored the first
workshop on Standards for DNA Practice in Africa.
Over 40 concerned biochemists and others from a
broad spectrum of organizations attended a series
of lectures presented by various authorities.
Three key issues identified were that, before
testifying, the forensic scientist will have to
prove that he or she is an expert, there must be
a standard operating procedure to achieve
desired performance standards, and a forensics
laboratory must be externally evaluated and
accredited.
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One outcome of the workshop was the establishment
of the African Society for Genetic Profiling
(ASGEP), whose objectives are 1. To provide a
forum to discuss DNA typing methods 2.
Standardization of DNA practices in Africa 3.
Standardization on STR loci, typing methods and
practices used 4. To co-ordinate and contribute
to a DNA statistical database and other
databases 5. To co-ordinate validation studies
of new DNA typing techniques 6. Setting of
accreditation guidelines and standards for DNA
typingmethods. Legislation is proposed for the
establishment of a forensic science council that
will have the responsibility of regulating the
setting of minimum standards applied by forensic
practitioners. A function of this council will
be to certify these practitioners and act as the
authority in determining educational and training
standards until such time as formal education for
the disciplines involved in forensic science has
been implemented.
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Conclusion
DNA typing has gained tremendous popularity in
the United States since its introduction in 1987.
Its possibilities are limitless. And with its
claims of mystic infallibility and virtual
certainty of identification, it is not surprising
that the law enforcement community has fully
embraced the technique. But some caution is
advised. In most of the initial cases involving
DNA printing, there were no challenges to the
reliability of the theory and technique, and only
very weak opposition to the specific laboratory
procedures. Now, however, concerns over the
reliability of laboratory procedures are being
expressed in the legal and scientific literature,
and media accounts of DNA typing are no longer
entirely favorable. Legal attacks in court have
become more intense, with judges rejecting DNA
evidence in some cases because of procedural
irregularities. The dialogue concerning the
reliability of forensic application of DNA typing
is healthy for all involved. Introspection by
the scientific community and critical
examination by the legal community will help
refine DNA typing to a point where no one will
lack confidence in its use. Then its true
potential can be fulfilled.