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Encyclopedia of Physical Science and Technology EN016H-959 August 1, 2001 11:6

910 Toxicology in Forensic Science

TABLE III Likely Extent of Postmortem Redistribution for A further problem relates to an assumption often made
Selected Drugs a by legal counsel (and indeed other parties) that a toxi-
Likely extent of postmortem cological investigation was exhaustive and all drugs and
Drug/drug class redistribution poisons were excluded in the testing processes. Most tox-
icology performed is restricted to a few analytical tests for
Acetaminophen (paracetamol) Low
a range of “common drugs and poisons,” unless the client
Alcohol (ethanol) Low
has made a request to examine for (additional) specific
Barbiturates Low to moderate
chemicals. Analysts should make courts aware of the ac-
Benzodiazepines Low to moderate
tual testing conducted and provide a list of substances in-
Cocaine Low
corporated in the investigation. Importantly, advice on any
Digoxin Very high
limitations applied to the interpretation of the analytical
Methadone Low to moderate
results should be provided (e.g., poor-quality specimens
Morphine Low
or postmortem artifacts). Above all, toxicologists must re-
Phenothiazines Moderate to high
strict their evidence to those areas for which they claim
Propoxyphene Very high
expertise. Stretching their expertise to apparently assist
Salicylate Low
the court can lead to incorrect or misleading evidence and
Serotonin reuptake inhibitors Low to moderate
damage the reputation of the expert.
Tricyclic antidepressants High
a These changes should only be used as a guide, as the environmental
conditions, length of time from death to specimen collection, and quality SEE ALSO THE FOLLOWING ARTICLES
of specimen can affect the extent of redistribution.
Note: Low = up to 20% elevation; moderate = 21–50%; high = 50–
200%; very high > 200%. ANALYTICAL CHEMISTRY • DNA TESTING IN FORENSIC
SCIENCE • ENVIRONMENTAL TOXICOLOGY • MASS SPEC-
TROMETRY IN FORENSIC SCIENCE • ORGANIC CHEMISTRY,
by diffusion from intestinal contents or from incomplete
circulation and distribution within the liver. COMPOUND DETECTION • SPECTROSCOPY IN FORENSIC
This process is particularly significant for drugs with SCIENCE
high lipid solubility, as these drugs tend to show concen-
tration differences in tissues and blood. Table III shows
the extent of these changes for selected drugs when com- BIBLIOGRAPHY
parisons are made between blood collected from the heart
and that collected from the femoral region. Baselt, R. H., and Cravey, R. H. (1996). “Disposition of Toxic Drugs and
The femoral blood is least subject to redistribution after Chemicals in Man,” 4th ed., Year Book Medical Publishers, Chicago.
de Zeeuw, R. A. (1997). “Drug screening in biological fluids: the need
death; however, drugs with much higher concentrations in
for a systematic approach,” J. Chromatogr. 689, 71–79.
muscular tissue will still diffuse through the vessel walls Drummer, O. H. (1998). “Adverse drug reactions.” In “The Inquest
and elevate the neighboring blood concentrations. If the Handbook” (H. Selby, ed.), The Federation Press, Leichhardt, NSW
femoral vessels are not tied off from the vena cava and Australia.
aorta, then the process of drawing blood can also extract Drummer, O. H. (1999). “Review: chromatographic screening tech-
niques in systematic toxicological analysis,” J. Chromatogr. 733,
blood from the abdominal cavity that has been contami-
27–45.
nated from diffusion of gastric and intestinal contents. It is Freckleton, I., and Selby, H. (1993). “Expert Evidence,” LBS
therefore advisable to reduce these processes by collect- Information Services, Sydney, Australia.
ing blood specimens as soon as possible after death from International Association of Forensic Toxicologists (TIAFT). (2001).
the femoral region with blood vessels tied off to reduce http://www.tiaft.org.
Karch, S. (1998). “Drug Abuse Handbook,” CRC Press, Boca Raton, FL.
contamination.
Levine, B. (1999). “Principles of Forensic Toxicology,” AACC Press,
Washington, D.C.
Maurer, H. H. (1992). “Systematic toxicological analysis of drugs
XI. COURT TESTIMONY AND EXPERTISE
and their metabolites by gas chromatography-mass spectrometry,”
J. Chromatogr. 118, 3–42.
Forensic toxicologists and other professionals called to Moffatt, A. C., ed. (1986). “Clarke’s Isolation and Identification of
give evidence in court should consider that much of their Drugs,” The Pharmaceutical Press, London.
technical evidence is beyond the ready comprehension of Siegel, J., ed. (2000). “Encyclopedia of Forensic Science,” Academic
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lay people in juries, legal counsel, and judges. Restricting
Society of Forensic Toxicologists (SOFT). (2001). http://www.soft-
one’s testimony to understandable language and simple tox.org.
concepts is highly recommended. United Nations. (1995). “Recommended Methods for the Detection