/ LEGAL FEATURE
opment languages, programming models, and
system architectures make it difficult for legal
professionals and juries to attain an under-
standing of the most elementary techni-
cal concepts. Take DNA evidence, for
example. When first introduced into
the legal system, DNA evidence and
expert witness testimony based upon
it, were not well understood, and
were sometimes challenged as new
or unproven science. Since then, DNA
exhibits have gone “mainstream” and
most jurors, conditioned by the popular
media to expect these types of exhibits,
would be surprised if DNA evidence were
not introduced at a criminal trial. Technology,
however, is a moving target, making it difficult
to build broad awareness and acceptance of a single
standard. As an illustration, virtualisation and cloud com-
puting architectures are new territory even for experienced
litigation attorneys with technical backgrounds.
Lastly, like many specialised domains, forensic science
is difficult to explain in laymen’s terms. This problem is not
unique to the computer forensic practitioner, and there are ex-
cellent resources for those interested in learning more about
conveying technical information. I have included a short list of
these at the end of this article. The key issue here is that one
of the most important jobs the expert witness is called to do,
is to translate highly technical, often terse information,
into language that can be clearly understood by a non-
technical audience.
/ Opinion Defensibility
The U.S. Supreme Court [Daubert v. Merrell Dow Pharma-
ceuticals, Inc., 43F.3d 1311 (9
th
Cir.1995)] has suggested
that expert witness testimony should be based on
scientific, repeatable, and reliable methods that are
generally accepted by the scientific community. What
does this mean and how does this apply to the work of
the forensic practitioner?
The work performed by a forensic practitioner
should be based on proven and documented
methods for collecting, processing, and analysing
digital information. This can be established in a
number of ways. One of the most common meth-
ods is by applying techniques that have been
taught by known and recognised authorities
in the field. This may include departmental or
agency training curricula, academic coursework
and degree programs, or commercial training
credentials. The training should be based on con-
sensus-developed, community-driven standards
to ensure admissibility of the work. Training and
proficiency with industry standard forensic tools
will help support the admissibility of an expert’s
work, but vendor product familiarity should be
only part of the picture.
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