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Science and law are two distinct professions that are
increasingly becoming co-mingled as technology develops (Bezak,
1992) Science Law Techniques to identify criminals have evolved at
a fast pace because of science. biological
markersEyewitness-dependent identification DNA anthropometry
fingerprinting fingerprinting 2
What pushed the paradigm shift from eyewitness accounts to
biological markers approach to criminal identification?The impetus
behind the development of biometric criminal identification
technologies in the late nineteenth century include factors such as
rapid urbanization; the increasing anonymity of urban life; and the
dissolving of local networks familiarity in which individuals were
known by their neighbours (Cole, n.d.) 3
AnthropometryAnthropometry is a system The Bertillon system was
using body measurements generally accepted for thirty of adult
individuals for years (German, 2012). personal identification
(Moenssens, 2008). Photographs and anthropometric descriptions are
used at a later time to identify a criminal, thus establishing
hisIt relies on the taking of the criminal history. measurements of
bony parts of the body, including DOWNFALL: measurements of the
cartilaginous human ear. 4
FingerprintingThe downfall of His report is anchored on the
anthropometry was used in documentation of 22 cases, the rise of
newer technology most involving violent crimes, in called
fingerprinting. which fingerprint evidenceGerman (2012) called this
as turned out to be dead wrong. the beginning of fingerprinting as
infallible Dye (2005) further iterated, means of personal however,
that the fingerprints identification did not lie; rather the
experts who matched them with aDye (2005) reported that a suspect
were wrong. study showed fingerprint evidence is not infallible.
5
DNA Fingerprinting Many highly polymorphic minisatellite loci
can be detectedGenetic information was simultaneously in the human
genome by hybridization to probes consisting of tandem repeats of
the core sequence. of seemingly peripheral interest to The
resulting DNA fingerprints produced by Southern blot hybridization
are comprised of multiple hypervariable DNA forensic scientists for
fragments, show somatic and germline stability and are a number of
years completely specific to an individual. (Saferstein, 2006) We
now show that this technique can be used for forensic purposes; DNA
of high relative molecular mass (Mr) can be isolated from 4-yr-old
bloodstains and semen stains made onIn 1985, this changed cotton
cloth and digested to produce DNA fingerprints when Alec Jeffreys
suitable for individual identification. reported in the British
Further, sperm nuclei can be separated from vaginal cellular Nature
Journal the debris, obtained from semen-contaminated vaginal swabs,
enabling positive identification of the male donor/suspect.
Forensic application of DNA fingerprints It is envisaged that DNA
fingerprinting will revolutionize forensic biology particularly
with regard to the identification of rape suspects. 6
Pate (n.d.), Vaca (1995) and Saferstein (2006) reported that
this process was the first scientifically accepted protocol in the
US for forensic characterization of DNA. 7
Semikhodskii (2007) describes the question whether or not DNA
evidence on its own is enough to convict an accused as one of the
most talked about points regarding evidence.Thompson (2008) in his
paper for the Council of Responsible Genetics entitled The
Potential for Error in Forensic DNA Testing (and How That
Complicates the Use of DNA Databases for Criminal Identification
argues that forensic DNA testing may bring about false
incriminations by means of (1) coincidental profile matches between
different people; (2) inadvertent or accidental transfer of
cellular material or DNA one item to another; (3) errors in
identification or labelling of samples; (4) misinterpretation of
test results; and (5) intentional planting of biological evidence.
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In 2009, Victorian Police Commissioner Simon Overland to order
his officers to stop giving DNA evidence in court proceeding over
concerns about discrepancies between the science and interpretation
of samples.Cole (n.d.) highlighted the objections against DNA
databases taking grounds on (1) the threat of eugenics; (2)
reliability of forensic evidence; and (3) breadth of databases.
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Based on case readings, doubts fall into the following themes:
1) coincidental profile matches; (2) unintentional attribution of
DNA profile to another; (3) unfounded threats like planting of
evidences and eugenics; and (4) breadth of database. Of these four,
only the first can be deliberated within the world of pure science
thereby crediting such doubts to DNA technology itself. 10
Coincidental Profile Match In the cases Thomson reviewed for
the past years, evidentiary samples from crime scenes are reported
to be often incomplete or partial DNA profiles. Limited quantities
of DNA can make it impossible to genotype at every locus (STR uses
13 loci as markers). In some instances, the test yields no
information about the genotype at a particular locus; in some
instances one of the two alleles at a locus will become
undetectable. Koehler (1993) supports that because partial profiles
contain fewer genetic markers than complete profiles, they are more
likely to match someone by chance. 11
Profile B and C are examples of partial DNA profiles. In both
cases these partial profiles would be deemed to match Profile A
because every allele in the partial profiles is also found in the
full profile. Hence, we have a coincidental profile match brought
about by partial DNA profiles. 12
Landmark cases of coincidental match: US. BBC News (2007)
reported that in 1999, in Swindon, a man with Parkinsons Disease
was arrested, and charged with a burglary in Bolton. He was frail
and had never been there. But his DNA sample matched one taken from
the crime scene (a 6 locus partial DNA as evidence). Similarly, in
2004, Sweeney and Main reported in Chicago Times that botched DNA
six locus partial DNA profile report falsely implicates a woman. A
as evidence was compared against a state offender database. When
the search produced a hit, the police arrested the woman but she
was eventually released considering a strong alibi of being in the
custody of a state prison at the time of burglary. 13
Unintentional attribution of DNA profile to another
Unintentional attribution of DNA profile to another could be
brought about by cross-contamination of samples, accidental
transfer of DNA from one sample to another, mislabelling of
samples, and misinterpretation of samples.Landmark cases: Rape
Case: Brian Kelly in Scotland Murder of a toddler Jaidyn Leskie in
Australia 14
Eugenics The argument is based on George Annas genetic
exceptionalism concept (Thompson, 2008). Genetic identification was
distinguished from supposedly harmless biometric identification
technologies like fingerprinting. Simply put, unlike fingerprints,
genes contain information about an individuals racial and ethnic
heritage, disease susceptibility, and even behavioural
propensities. The author put it simply with insurance companies,
employers or other government agencies might raid the data for
health-related data, leading to genetic discrimination against
individuals or groups. 15
Gans and Urbas (2002) maintain the benefits of DNA
identification in the Criminal Justice System. They presented
twelve significant Australian DNA cases.One of which is that of
Desmond Applebee within the Australian Capital Territory. This was
the first use of DNA evidence in Australian criminal proceedings.
The accused was charged with sexual assault and initially denied
any contact. He altered his defense to consensual intercourse after
DNA evidence was admitted as part of the case. He was eventually
convicted by the jury. 16
In light of the issue on coincidental profile match, Kaye and
Sensabaugh (2000) and Freckelton and Selby (2000) advocate ways to
reduce error. The number of DNA features profiled can be increased.
Similarly, possible suspects can be tested or excluded by mass
screenings or database searches.As previously noted, unintentional
attribution of DNA profile to another could be brought about by
cross-contamination of samples, accidental transfer of DNA from one
sample to another and mislabelling of samples. Errors brought by
these unintentional attributions can be reduced by separating the
profile of suspect and crime samples. In addition, stringent crime
scene and laboratory protocols can be introduced to avoid
contamination. And if possible, a part of the crime sample could be
preserved prior to testing. 17
Contrary to eugenics, the National Institute of Justice (2000)
and van Ooschot, et al. (2001) argue that the present limits of
genetic science means that a direct analysis of a persons DNA will
yield only limited information about individual characteristics.As
to the strength of DNA fingerprinting, there have been no known
false DNA matches in Australia, but there have been noteworthy
instances in other countries (the previously discussed cases in UK
and Chicago). Similarly argued by Gans and Urbas is that the errors
in the handling of samples or the reporting of results can be
largely avoided through protocols. 18
Following Muellers conclusion, DNA typing can be a powerful
tool in forensics (1993).The risks of false or misleading results
attributed to DNA fingerprinting should not be considered as just
cause to reject its use in criminal investigations and
identification. This is most typical when there is independent
evidence about a suspects guilt or innocence.Another concern
highlighted by this review is the need for policies and protocols
which would ensure that laboratories carrying out DNA
fingerprinting would perform the tests with the highest accuracy
possible. 19