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1. Victim Selection

• 89% did not know their victims before the crime, and 29% had

met or previously seen at least one of their victims (some killers
attacked both strangers and acquaintances);

• 50% offered their victims rides, 11% met them in bars, and 7%

contacted them through newspaper advertisements;

• 86% randomly selected their victims; and
• 25% murdered prostitutes, and 21% were attracted to children

(girls under the age of 12 years).

2. Hunting

Behaviour

• 32% planned their murders in advance, and 61% were familiar with

the area where the crime was committed;

• 18% followed and 18% hunted their victims; and
• 46% operated with an accomplice, 32% with a male and 14% with

a female.

Table 9.1 Holmes and De Burger Serial Murderer Typology

Serial Murderer Type

Victim Selection

Method

Crime Locations

Visionary

known & stranger
nonspecific
random

spontaneous
disorganized

concentrated

Mission-Oriented

stranger
specific
nonrandom

planned
organized

concentrated

Hedonistic Lust

stranger
specific
random

planned
organized

concentrated
body movement

Hedonistic Thrill

stranger
specific
random

spontaneous
disorganized

dispersed
body movement
geographically stable

Hedonistic Comfort

known & relational
specific
nonrandom

planned
organized

concentrated

Power/Control-

Oriented

stranger
specific
nonrandom

planned
organized

dispersed
body movement
geographically transient

Opportunist

stranger
nonspecific
random

spontaneous
disorganized

dispersed

3. Transportation

• 78% used vehicles, either directly or indirectly, in the commission

of their crimes;

• 50% of those who directly used vehicles in their crimes offered their

victims rides;

• 54% drove their own vehicle, 9% a relative’s, and 18% used a stolen

automobile; and

• 7% used public transportation, and 4% flew an aircraft.

4. Attack

• 75% of the serial murderers conned their victims to gain control,

and 68% used a ruse to get them to the attack location;

• 21% employed immediate force to gain control; and
• 32% attacked on their own property, 29% on the property of a

relative or friend, and 29% in the victim’s residence.

5. Body

Disposal

• 64% tried to conceal their victims’ bodies in remote areas;
• 29% buried their victims underground, and 21% dumped them in

water; and

• 68% moved the bodies of their victims after the murder.

6. Apprehension

• 61% had a previous criminal record;
• 11% had been observed within the crime area by police, and 18%

were connected to the crime area by patrol officers;

• 29% had been questioned and then released;
• 14% were arrested through surveillance methods, and 8% through

patrol work;

• 31% were caught as the direct result of police investigation activi-

ties, and 61% from witness information; and

• 32% kept incriminating evidence at their home or workplace, and

29% on their person or in their vehicle (some murderers did both).

Wingo classifies serial killers as “megastat,” those who kill over time in

a single static urban environment, or “megamobile,” those who are mobile
and travel over great stretches of geography (Egger, 1990). In their study of
sexually sadistic criminals, Dietz et al. (1990) note that 40% of their subjects
(n = 12) engaged in “excessive driving” (travelling long distances or with no
clear direction). Davies and Dale (1995b) observe many British rapists are
incessant prowlers, cruising by vehicle, public transportation, or foot. This
finding has been confirmed in both U.S. and Canadian studies, underlining
the investigative importance of recording information on prowlers, trespass-
ers, and suspicious persons. Viable sexual assault suspects can often be found
through such records when queried by geographic area.

Mobility, however, does not necessarily translate into range. Keppel (1989)

notes “serial killers are highly mobile, frequently cruising and drawn to those
victim contact areas where they feel they are in their ‘comfort zone’ ” (p. 65).
Such offenders typically have ready access to vehicles which they use to become
familiar with their preferred victim encounter and body disposal areas. Keppel
cites the examples of Wayne Williams and John Wayne Gacy, Jr., both of whom
confined their murderous activities to a single metropolitan area — Atlanta and
Chicago, respectively. The mobility associated with serial murderers can result
in a higher frequency of cruising, but not necessarily in greater geographic reach.

Hickey (1997) found three geographic categories of offender in his study

of serial murder: (1) travelling killers (34%), who commit murder while mov-
ing through or relocating to other areas; (2) local killers (52%), who remain
within a certain urban area, or a single state; and (3) place-specific killers
(14%), who murder within their own home, workplace, or other specific site.
Local serial murderers are responsible for fewer victims per offender than
travelling or place-specific killers, both of whom are harder to apprehend.
Linkage blindness is a significant problem with mobile offenders, and author-
ities are often not aware that a place-specific murderer is active. Hickey (1990)
observes a shift in mobility patterns post-1975, with an increase in local serial
killers and a reduction in out-of-state travelling and place-specific offenders.
He suggests these shifts may be due to increased urbanization, advances in
techniques of forensic analysis, and changes in methods of murder.

Newton (1992) studied 301 U.S. and 56 non-U.S. serial murderers from

a 20-year period, and classifies them by hunting style into: (1) territorial
killers (63% of U.S., 70% of non-U.S. cases), who stake out a defined area;
(2) nomadic killers (29% of U.S., 15% of non-U.S. cases), who travel widely
in their search of victims; and (3) stationary killers (8% of U.S., 15% of non-
U.S. cases), who commit their crimes at home or work. Newton notes that
serial murderers usually follow the same hunting style, which he feels
expresses their view of life and who they are.

These results contradict the generally held assumption that serial killers

are highly peripatetic (Egger, 1984; Keppel, 1989). Levin and Fox (1985)
found “traveling serial killers ... are a minority to those ... who ‘stay at home’
and at their jobs, killing on a part-time basis” (p. 183). Serial murderers tend
to be geographically stable, killing in areas they know. Turf is a valued com-
modity and Barrett (1990) suggests offenders avoid hunting in areas besieged
by other killers, though this might be best explained by the scarcity of the
phenomenon. Newton (1992) comments that the majority “rarely deviate
from the selected game preserve” (p. 48). Perhaps executed serial murderer
Donald “Pee Wee” Gaskins said it best: “I felt safer doing my killing and
burying in my home state. I guess I’m just a Carolina Southern-boy at heart”
(Gaskins & Earle, 1993, p. 161).

Serial murder victims are more often attacked outside their home than

other homicide victims because of the crime’s stranger nature, and potential
victims are more vulnerable in areas where such killers have ready access.
Hickey (1997) found female serial child killers are more likely than their male
counterparts to be place-specific (33% vs. 13%), and male serial child killers
more likely to be travellers (46% vs. 21%). This result reflects the institutional
nature of the locations involved (e.g., hospitals, boarding houses, etc.)
involved. Most employed female serial murderers use their occupational
position to access victims (Scott, 1992; Segrave, 1992).

In their study of serial rape in England, Canter and Larkin (1993) applied

the circle hypothesis as a means of dividing offenders into “marauders” or
“commuters.” An offence circle is the region enclosed by the circumference
of the circle, the diameter of which is the line joining the two most distant
crimes. Marauders are individuals whose residences act as the focus of their
crimes. Commuters, on the other hand, travel from home into another area
to commit their offences. The circle hypothesis suggests that marauders reside
within their offence circle, and commuters reside without. Only 13% of the
British serial rapists (n=45) had a home base outside of their offence circle.
Finding little support for the commuter hypothesis, the research concluded
that rapists, like most people, are typically “domocentric.”

Kocsis and Irwin (1997) caution, however, that the generality of this

conclusion is doubtful. In a study of Australian serial offenders, they noted
that 71% of rapists, 82% of arsonists, and 48% of burglars resided within
their offence circle. The FBI found 51% of U.S. serial rapists (n = 76) lived
outside of their offence circle, and 76% outside of the convex hull polygon
(see above) created by their crime site pattern (Warren et al., 1995). Alston
(1994) had similar results to those of the FBI in his study of 30 British
Columbia stranger sexual assault series; in 43.4% of the cases the offence
circle did not contain an offender activity node. National differences in urban
structure, neighbourhood density, and travel behaviour might contribute to
the inconsistencies in these findings (Warren et al., 1995).

One of the problems with the circle hypothesis is its determination of

hunting behaviour solely from the crime site point pattern (see Alston, 1994,
for a discussion of other issues of concern). In cases involving large numbers
of offences, a rapist may commute to several different areas in various direc-
tions, creating an offence circle that contains his residence. And in cases
involving small numbers of crimes a marauder might find by chance all of
his victims in the same direction, resulting in an offence circle that excludes
their home base. Offence circles could therefore lead to both commuter and
marauder designations, depending upon what point in a serial rapist’s career
they were generated.

This happened in both the Yorkshire Ripper and the

Boston Strangler cases (Burn, 1984; Davies & Dale, 1995a; Frank, 1966). In

other instances a nonuniform target backcloth may force a commuter pattern
regardless of the offender’s hunting style.

As part of a suggested taxonomy of rape series, Alston (1994) proposes

marauders be defined as those offenders who consistently travel under 5
kilometres from a primary activity site (e.g., home or work) to the initial
victim contact scene, and commuters as those who travel more than 5 kilo-
metres. He observes the latter tend to stay close to the major thoroughfares
used for their crime journeys. Davies and Dale (1995b) caution “that the
commuter and marauder models may just be extremes of a continuum of
patterns determined by topography and target availability” (p. 16).

9.2 Geography of Serial Murder

Descriptive accounts of serial murder and rape spatial patterns are useful,
but a greater understanding of offender behaviour is gained by applying
theories and techniques from environmental criminology and quantitative
geography (Brantingham & Brantingham, 1984; R. V. Clarke, 1992, 1997;
Garson & Biggs, 1992; Taylor, 1977). To this end, a seven-year research project
on geographic profiling and target patterns of serial murderers was conducted
at Simon Fraser University’s (SFU) School of Criminology (Rossmo, 1995a).
The study involved the collection and analysis of two forms of data: (1)
macrolevel information on serial killers; and (2) microlevel information on
offenders, victims, and locations for selected serial murders.

Within a geography of crime perspective, locations of crime sites are seen

to be influenced by hunting style, target backcloth, and changes in offender
activity space. Some of the related questions this study sought to answer
include: (1) which crime location types, individually or jointly, are the best
predictors of offender residence; (2) what do the characteristics of the crime
site and surrounding area tell us about the offender; and (3) is it possible
earlier crimes, committed before the killer gained experience and expanded
his or her spatial repertoire, are better indicators of an offender’s home area?
The SFU serial murder data set provided the information necessary for an
analysis concerned with these and other issues. Area and neighbourhood
characteristics, victim types and activities, date and time periods, and
offender mobility were examined. Data were also available to compute crime
trip distances, size of hunting area, degree of pattern aggregation, and week-
day of offence.