216
Principles and Practice of Criminalistics
The Hillside Stranglers — “A”
is for Ant
When journalists dubbed the killer of several prostitutes in the late 1970s as the Hillside Strangler,
little did they realize that they were actually writing about
two
killers. Forensic
science played its role
in providing information about the case, including one small aside that did not figure prominently
in the outcome of the trial, but illustrates the necessity of knowing as much about the case as possible.
The origin of the infamous moniker arose from the proclivity of the killers to dump the nude,
strangled bodies onto inaccessible hillsides, presumably in hopes that the bodies would not be found.
One such victim was a woman who was discovered early one morning. A
sharp-eyed detective noticed
a trail of ants streaming to one of her breasts. He naively suggested that this might be due to the
presence of saliva on the breast, which the ants were consuming as food. He insisted that the criminalist
at the scene collect a nipple swab to collect any saliva that might be present.
At the laboratory, the analyst examined the swab for amylase, a component of saliva. He detected
“moderate” amounts of amylase in a semiquantitative spot test. No control
samples had been collected
from other locations on the skin of the deceased, so the meaning of this result was problematic from
the beginning. However, the analyst then performed an absorption–inhibition test for ABH antigens.
He detected type B (no H) activity. The report indicated the presence of moderate amounts of amylase
and the presence of B antigenic activity. The reader was left with the impression that saliva from a
type B-secretor was present. The victim in the case was an type O nonsecretor, and so the antigenic
activity could not have been from her.
Research from a previous case had indicated that
ants possess some ABH activity, and so, even
assuming saliva was present (which is not necessarily supported by the amylase finding), some question
existed regarding the source of the antigenic activity. In an effort to find out more about this possibility,
the analyst consulted with Dr. Roy Snelling, a leading entomologist from the California Museum of
Science and Industry. The expert readily identified the ants on the body as a species of fire ants. He
also agreed to assist the analyst in collecting a sample of these ants. They went to the scene of the
body dump, and laid ingenious traps containing raw bacon to lure and trap only the carnivorous fire
ants. Other species of ants at the location would either ignore the traps
or be driven away by the
aggressive and warrior-like fire ants. Sure enough, when they returned the following day, the traps
contained several hundred fire ants for the analyst to take back to the laboratory. Additionally, Snelling
was able to provide numerous references to the gustatory habits of ants, revealing poor table manners
and the tendency to slobber. This research also revealed that previous assays for amylase were, indeed,
positive.
In the laboratory, the ants were tested for both amylase activity and ABO. Not
surprisingly, these
ants had amylase activity, as indicated by the past research. Further, these fire ants had type B antigenic
activity. The analyst was unwilling to assume that the ants were in fact the source of the amylase and
antigenic activity on the breast swab, but at least these findings created a reasonable alternative
hypothesis for the evidence. The attorney prosecuting the defendants decided
to hold this evidence
for rebuttal, rather than use it in the case in chief.
Because he was a type AB non-secretor, the defendant immediately seized on the report
implying a saliva donor that was a type B secretor. After seeing the prosecution’s report detailing
the results of the ant analysis, the defendant retained its own forensic expert to assess the evidence.
This expert also
retained an entomologist, and the two of them toddled off to the crime scene to collect
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Good Field Practice — Processing a Crime Scene
217
is the implementation of measures designed both to prevent negligent con-
tamination and to detect it in the rare event that it occurs. Prevention of
contamination introduced by law enforcement, crime laboratory personnel,
or any extraneous human beings starts at the crime scene. We’ll
address the
prevention and detection of contamination in the laboratory in Chapter 10.
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