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f.
Interpretation and Conclusions
The internal reviewer should independently form his own conclusions from
the data and compare them with the analyst’s. Any differences in interpretation
make for useful discussion. If the analyst or examiner and the reviewer
cannot, in good faith, resolve any differences in interpretation, they should
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Principles and Practice of Criminalistics
consider whether the results are sufficiently reliable to be presented in a report
or a court of law.
Another point that is not always highlighted in the laboratory report is
any inherent weaknesses in the case or the data. These may have nothing to
do with the laboratory or the analysis. Rather they are integral to the evidence,
the test, or the case. For example, the evidence may be quite common, or
the evidence may be of poor quality such that a comparison is difficult, or
it may be unclear how the evidence relates to the case.
The reviewer’s most important role is to determine if the conclusions are
supported by the data. This is difficult to do if the laboratory has not supplied
a conclusion. One of the most annoying things an independent reviewer will
encounter is a report that stops with a simple listing of the results. WHAT
 
Figure 9.2
 
Calculations.
Which columns don’t add up? Careful inspection by
both the analyst and recalculation by a reviewing analyst will minimize the
opportunities for such an oversight to emerge from the laboratory in a report.
.
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DOES IT MEAN? Either by design or default, the analyst has failed in his
ultimate obligation — to provide his best interpretation of the results to the
client as well as opposing counsel, the judicial system, and anyone else who
reads his report. Sometimes this is a game played by certain laboratories to
facilitate ambush in court; other times it is simply entrenched, institutional
policy. There is usually little a reviewer can do to extract conclusion from a
laboratory not used to providing one.
In a more subtle and also more common variation, the laboratory will
report only one out of several equally possible conclusions. For example, the
attorney has asked the question of whether a particular suspect is included
as a contributor to the results. It may not be untrue to include the suspect,
but neither may it always be complete. It is up to the reviewer to expose all
reasonable interpretations of the data, and to predicate various conclusions
on the appropriate assumptions. We will talk more about the analyst’s obli-
gations in this area in the Chapter 12.
An independent reviewer, looking at the same data as the analyst, may
interpret the data differently and may come to a different conclusion about
its meaning. One way in which this can happen is when the two scientists use
different assumptions to modify the facts. For this reason, both should artic-
ulate any assumptions to help clarify the basis of any differing conclusions