8127/frame/fm

 
C.
The Evidence
If you don’t recognize it, you cannot collect it; if you don’t collect it, you
cannot analyze it; if you don’t analyze it, you cannot interpret it.
 
1.
Recognition
We spent a large part of Chapter 5 discussing the recognition of evidence.
Recall that this involves more than just a mindless visual scan. Recognizing
evidence that is actually relevant to a crime requires looking with purpose.
One must have in mind a putative scenario, a preliminary hypothesis, and
some plausible alternative hypothesis. Might this cause you to miss evidence
that could point to a different scenario? Perhaps, but it is still preferable to
searching blindly. The key to recovering evidence is to consider alternative
hypotheses. Because it is impossible to search everywhere, a directed search
provides the best chance of finding enough relevant evidence to assist in
solving the crime. Accept that you will always miss something; it’s the nature
of the business. No crime scene search is perfect. The job of the crime scene
team is to minimize egregious oversights by processing the scene with
thoughtful intelligence.
 
2.
Detection
Not all evidence will be in plain sight. Some will be blocked from normal
view, for example, fingerprints underneath a table; some will be physically
obstructed, for example, a body buried in the crawl space. Not infrequently,
evidence will be in plain sight, but out of our normal field of view, for
8127/frame/ch08 Page 207 Friday, July 21, 2000 11:45 AM

---

208
Principles and Practice of Criminalistics
example, on a ceiling or roof. One of the more productive tenets of crime
scene investigation is always to look up. Other evidence will require special
methods of detection to visualize it. This aspect of criminalistics, in partic-
ular, has captured the imagination of both mystery writers and practitioners.
Methods for making the invisible visible, and for instantly determining the
nature of a substance, feed our compulsion for immediate gratification and
satisfy our curiosity. Note that to discover latent evidence, one must have
some idea of what to look for and where to look.