Файл: [D._Kim_Rossmo]_Geographic_Profiling(BookFi.org).pdf

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loitering, trespassing, peeping, etc.) in their backgrounds, and the locations
of their past offences may overlap with the present ones.

11.1.3 Task Force Management

Task force operations formed to investigate a specific series of crimes often
collect and collate their information in some form of computerized major
case management system, such as the British HOLMES or FBI Rapid Start
programs (Federal Bureau of Investigation, 1996; U.S. Department of Justice,
1991b). Cases suffering from information overload will benefit from the
prioritization of data and the application of correlation analysis (Keppel &
Birnes, 1995). Geographic profiling can assist in these tasks through the
ranking of street addresses, postal or zip codes, and telephone number
(NNXs) areas.

Figure 11.1

    Lafayette South Side Rapist — crime sites.

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This process can also be linked to information available in CD-ROM

telephone directory databases listing residential and business names, tele-
phone numbers, addresses, postal or zip codes, business headings, and stan-
dard industrial classification (SIC) codes. The details of the specific task force
computer database software, including information fields, search time, num-
ber of records, and correlational abilities, determine the most appropriate
form the geographic profile should take to maximize its usefulness to the
police investigation.

11.1.4 Sex Offender Registries

Violent sex offender registries are a useful information source for geographic
profiling in cases of serial sex crimes (Popkin, 1994). By providing a list of
addresses of known sex criminals, these registries can be used with a geo-
graphic profile to help prioritize suspects. The U.S. 

Violent Crime Control

and Law Enforcement Act of 1994

 “requires states to enact statutes or regula-

tions which require those determined to be sexually violent predators or who
are convicted of sexually violent offenses to register with appropriate state
law enforcement agencies for ten years after release from prison,” or risk the
reduction of Federal grant money (U.S. Department of Justice, 1994a).

Sex offender registries are powerful tools for monitoring and controlling

criminal predators who, unfortunately, are more prevalent than is commonly
believed. Washington State established the first such registry, and according
to the Seattle Police Department Special Assault Unit, in May of 1995 the
City of Seattle had a total of 859 registered sex offenders, an average of 10
per square mile. This figure does not include the 20% of released sex offenders
who fail to register.

11.1.5 Government and Business Databases

Data banks are often geographically based and information from parole and
probation offices, mental health outpatient clinics, social services offices,
schools, and other agencies located in prioritized areas can also prove to be
of value (it has been estimated that approximately 85% of our records contain
an address). LeBeau (1992) discusses the case of a serial rapist who emerged
as a suspect after police checked parolee records for sex offenders. Private
businesses may also contain information of interest. In one case involving a
series of sexual assaults, the criminal profile suggested the offender was likely
a frequent user of pornography. An SIC code search for video stores on a
CD-ROM telephone directory produced a list, which was then prioritized by
address according to the geoprofile. Investigators could then use this infor-
mation to focus on prioritized stores, showing composite suspect sketches,
and checking frequent renters of adult video titles, knowing most people

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frequent video stores close to home. Similarly, prioritization of automobile
service stations is useful if a suspect vehicle description has been obtained.

11.1.6 Motor Vehicle Registrations

A geographic profile can be integrated with suspect vehicle and offender
descriptions to search registered motor vehicle and driver’s licence files, con-
tained in provincial or state computer record systems. This is often done by
first using the geoprofile to prioritize postal or zip codes most likely associated
with the offender’s residence. The description and geographic parameters act
as a linear program to produce a small set of records containing the appro-
priate data. This strategy results in areas of manageable size for major police
investigations.

A case example involving a violent child sex offender illustrates this point.

The postal codes for the neighbourhood within which he was attacking
children were prioritized from the geoprofile. Planning and zoning maps
were then used to eliminate industrial, commercial, and other nonresidential
areas. Socioeconomic and demographic census data were also consulted to
reevaluate the priority of those neighbourhoods that were inconsistent with
the socioeconomic level of the offender as suggested by the criminal profile.

The final list of postal codes, ranked by priority of probability, could then

be used to conduct a computer search of the provincial motor vehicle depart-
ment records which contain postal codes as part of the address associated
with the vehicle registered owner and driver’s licence files. Suspect vehicle
and offender descriptions had been developed by detectives, and this infor-
mation was combined with the geographic data to effectively focus the search.

For example, a new red station wagon driven by a tall white middle-aged

male, with dark hair, may seem to be somewhat vague information. But the
description actually contains several parameters: (1) vehicle style — station
wagon; (2) vehicle colour — red; and (3) vehicle year range — last 5 years.
Additional focus results from the various driver descriptors (e.g., sex, race,
age range, height, hair colour, etc.), though the assumption that the driver
is the vehicle’s registered owner may be incorrect. These parameters can
narrow down hundreds of thousands of records to a few dozen vehicles or
drivers when combined with a prioritized list of postal or zip codes. This is
sufficient discrimination to allow detailed police follow-up (see Ressler &
Shachtman, 1992, for an example of a murder investigation involving a
computerized vehicle search without such geographic discrimination).

11.1.7 Patrol Saturation and Stakeouts

The geoprofile can be used as the basis for directing saturation patrol and
police stakeouts. This strategy is particularly effective if the crimes occur

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during specific time periods. Many criminals spend a significant amount of
time searching for targets, while others wait in particular areas for suitable
victims and the right circumstances. Police have a much greater chance of
observing an offender prowling or loitering than in an assault simply because
considerable more time is spent hunting than attacking. It has been estimated
that some criminals exhibit hunt to attack ratios in excess of 10:1.

Kentucky police, correctly anticipating the movements of a serial killer

from the pattern of his crimes, set up road blocks in a park to question late
night motorists (Barrett, 1990). This tactic gathered over 2000 names for the
purpose of cross-comparison with other investigative information. Through
a geographic analysis of the crime sites in the Atlanta Child Murders, Det-
tlinger came to the conclusion the killer was commuting along certain city
routes (Dettlinger & Prugh, 1983). But his suggestion that stakeouts be estab-
lished at the crucial points in this spatial pattern went unheeded by police,
and five more bodies would be dumped near these locations before Task
Force officers staking out a Chattahoochee River bridge pulled over Wayne
Williams.

11.1.8 Response Plans

Additional police responses in the event of a new crime may be developed
with a geographic profile. Many criminals return home after committing a
crime, and patrol units can be directed to the area of probable offender
residence, in addition to responding to the crime scene. Particular attention
should be paid to the most logical routes from the crime site to the high
profile area, and to relevant major arterial streets, freeways, and off-ramps.
Roadblocks may also be an option. This strategy is only appropriate for those
cases in which there is no significant time delay in reporting of the crime.
Depending on the size of the hunting area, the offender’s probable escape
routine might also suggest possibilities for locating witnesses. Gasoline sta-
tions, cafés, pubs, and other services along the likely routes between the crime
sites and the peak geoprofile area can be identified and canvassed. Closed
circuit television (CCTV) and commercial video cameras can similarly be
checked.

In serial murder cases, police response plans can be developed in the

event of the discovery of a new body dump site. Some killers reuse previous
body dump sites; other offenders have been known to repeatedly visit their
crime sites between killings for the purposes of fulfilling sexual fantasies. If
the discovery of a new body dump site can be kept secret from the media,
police surveillance may catch the offender revisiting the location.

Chapter 10, Color Figure 1

    Vancouver robberies—Jeopardy surface.

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