8127/frame/fm

 
Figure 11.2
 
Example of a poor report. 
This report was received by a state lab-
oratory from an independent consultant only after an order by the judge. It has
been retyped for clarity, following the format as closely as possible within the
confines of space and legibility. All identifying information has been omitted or
generalized. Note that the report fails to mention which, if any, of the stated
potential “inherent problems in STR testing” pertains to the case at hand, and
how that problem might affect the interpretation of the results. Note, also, that
the report fails to provide an independent interpretation of the results, stating
only that they “can be interpreted differently.”
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Communicating Your Results — Where Science Meets the Law
279
in each of three separate stains, blood from both the victim and the defen-
dant was present as a mixture. Recall that seven PCR-based DNA markers
exhibited the same types as the victim. One serological marker, 
 
PGM
, exhib-
ited the same type as the defendant. Their report consisted of a table of
results. No conclusions were drawn about the inclusion or exclusion of
various principals, and no interpretive prose was to be found. The analysts
testified in court that, although no evidence of a mixture was apparent,
their conclusion was that the data resulted from a mixture of the victim
and defendant. The data were clearly inconsistent with their testimony.
Likely, they had only constructed the explanation after receiving a written
report from an independent expert detailing a different opinion.
If the analyst is convinced that the data support a particular conclusion, this
should be stated in the written report; if the data are uninterpretable or
inconclusive, this information is just as important and should also be stated.