8127/frame/fm

4.
Association
Association
may be the most misunderstood concept in the forensic arena.
Although it is intimately associated with the concept of transfer, and entirely
dependent on the processes of classification and individualization, few
records exist of any academic discussion of association per se or its relation-
ship to other forensic concepts. Kirk (1953) skirts the edges of this discussion
when he suggests that inanimate objects can serve as intermediary evidence
in the course of linking a person with a crime.
The central problem of the criminal investigator is the establishment of
personal identity. Usually this is the identity of the criminal, sometimes the
identity of the victim. Supplementary to the establishment of personal
identity is the establishment of the identity of physical objects, which in
turn contributes to the desired personal identification. The identification
of a murder weapon may lead to its possessor at the time of the crime.
Identification of handwriting leads to the writer and so forth.
Osterburg (1968) describes associative evidence merely as “linking a person
to a crime scene.” Likewise in DeForest, Lee, and Gaensslen’s 
Forensic Science:
An Introduction to Criminalistics
(1983), only a couple of sentences are
devoted to this essential notion.
8127/frame/ch02 Page 56 Friday, July 21, 2000 11:51 AM

---

The Evolution of Forensic Science
57
Depending on the degree of individuality exhibited by the samples, various
conclusions can be drawn about the association between people and the
physical evidence in the case.… These kinds of considerations need to be
kept in mind when evaluating the value of 
associative
physical evidence
comparisons.
Even here, we are not sure whether association is a synonym for individual-
ization or a completely different concept. As we will see in the next chapter,
association may best fit into the forensic paradigm as the culmination of
classification or individualization. In fact, it best describes the basis for a
conclusion of contact between two objects.
Probably the most recent thinking on the matter comes from Evett et al.
(1998). These workers propose a “hierarchy of propositions” within which
to consider levels of association in casework. The levels they suggest are
(1) 
source
(e.g., the glass fragments came from window X; (2) 
activity
(Mr. A
is the man who smashed window X); (3) 
offense
(e.g., Mr. A committed the
burglary). They emphasize that at each level, the scientist must also consider
the alternative hypothesis, i.e., the glass fragments came from some other
broken glass item; Mr. A did not smash the window; another person com-
mitted the burglary. In Section 2 of this book, we will see that Evett’s hierarchy
simply provides different terms for concepts with which we are already famil-
iar. 
Source
is analogous to 
classification
/
individualization
; 
activity
we under-
stand as 
association
, and 
offense
directly correlates to 
reconstruction
.