By David M. Benjamin, PhD
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LEARNING OBJECTIVES:
After attending this presentation, the participant will understand: (1) the
special problems encountered in analyzing biological samples obtained from embalmed/exhumed
bodies, (2) the limitations of conventional immunoassay and chromatographic
analytical "screening test" when applied to biological samples obtained from
embalmed or exhumed bodies, and (3) the importance of confirmatory testing in
providing scientifically reliable evidence.
Forensic toxicologists
are frequently required to analyze biological specimens obtained from embalmed
or exhumed bodies for the presence of drugs. Often, the first line of approach
are rapid, inexpensive immunoassay procedures such as the enzyme-mediated immunoassay
(EMIT) or the radio immuno assay (RIA), or chromatographic procedures such as
Thin-Layer Chromatography (TLC), Gas-Liquid Chromatography (GLC), and High-Pressure
Liquid Chromatography (HPLC). However, immunoassays and chromatographic procedures
are not specific for a particular analyte molecule and cross-reactivity with
chemically-related molecules can occur leading to false positive results. In
order to confirm the presence of a substance determined to have been present
in a screening procedure, the use of a confirmatory Mass Spectrometry (MS) test
is generally recognized as the "Gold Standard". Usually, the analyte is isolated
from the biological samples by acidic or basic extraction into an appropriate
organic solvent, followed by separation from other biological and xenobiotic
molecules by Gas Chromatography (GC). The purified analyte molecule is then
directed into the MS for analysis based on the appearance of fragments of the
parent molecule which are specific only for the substance under analysis.
The case of Commonwealth
of Massachusetts v. Christina Martin is an example of how the unconfirmed results
of analytical testing for LSD came under suspicion and resulted in the 1999
release of Ms. Christina Martin from prison, where she had been incarcerated
since her November 13, 1992 jury conviction for first degree murder. Christina
Martin was 35 years old, and lived with her 61 year old boyfriend Richard Alfredo,
the decedent, her 14-year old daughter Teasha, and one other child. Mr. Alfredo
had long-standing cardiac disease and had undergone cardiac bypass surgery years
earlier. Based on Teasha's report that Mr. Alfredo had sexually abused her,
Christina, the mother, promised her daughter that she would make him hurt for
his misdeeds. Both then tried to purchase mescaline on the street, however,
upon telling the local youths that they intended to kill the boyfriend, the
youths sold them bogus drugs. Allegedly, the pair was ultimately successful
in purchasing real mescaline, some of which Teasha ingested and "verified" as
active. They then proceeded to prepare Jello containing the illicitly-obtained
drugs and administered the Jello to the boyfriend. On January 21, 1990, ten
or so minutes after ingesting the "poisoned" Jello, Richard Alfredo suffered
a heart attack and died. In view of the decedent's history of heart disease,
the manner of death was believed to have been natural; however based on Teasha's
disclosures to her friends, the previously-embalmed body was exhumed 31 days
later for forensic analyses. A large amount of ground water had gotten into
the casket, and a video-tape of the autopsy showed the medical examiner literally
"ringing out" the body organs as he removed them from the body cavity.
Using
the Roche Abuscreen RIA screening test, the Crime Laboratory of the Commonwealth
of Massachusetts detected the presence of LSD in specimens of blood, urine,
CSF, intestinal contents, vitreous fluid, and chest fluid; however, confirmatory
testing with GC-MS was negative. In order to obtain a confirmed presence of
LSD, the Commonwealth forwarded samples obtained from the coffin to National
Medical Services for further testing. Once again, using RIA and chromatographic
techniques, LSD was reported positive in cavity fluid, urine, arterial fluid
and intestinal fluid. Blood samples also showed the presence of diphenhydramine
(Benadryl), an antihistamine Mr. Alfredo was taking for what he believed to
be a cold or flu. At trial, Dr. Sagall, a local cardiologist with no training
in toxicology or experience in treating LSD toxicity, and who, relying solely
on "several textbooks" he read, testified that LSD could increase the heart
rate, and that such tachycardia caused a heart attack in Mr. Alfredo due to
his long-standing cardiac condition. However, Dr. Sagall neglected to mention
that Goodman and Gilman's textbook, upon which he relied, also stated that "In
man, deaths attributable to direct effects of LSD are unknown", and that diphenhydramine
is a powerful anticholinergic agent even more capable of producing a tachycardia
than LSD. Following a hearing for a new trial at which this author testified,
and an appeal by the Commonwealth to the Supreme Judicial Court of Massachusetts,
a new trial was granted. Ultimately, the Commonwealth reduced the charges to
Manslaughter and time served and Ms. Martin was released.
By: David M. Benjamin, PhD. Reprinted with permission
from Dr. Benjamin. Website: http://www.channel1.com/users/medlaw/