Notable Accounts of Crime Analysis in Action
Glendale Police Department
Glendale, AZ
Submitted by Peggy Call, Crime Analyst
Salt Lake City, UT Police Department
Scenario:
In March and April 2001, a
suspect dubbed the "Video Bandit" committed 11 robberies and one
homicide at video stores throughout the "Valley of the Sun" (Phoenix-Glendale,
AZ). There was very little description
to go on for the suspect and he was often reported to be either a White or
Hispanic male. He was reported to have
used a red vehicle, possibly a Saturn in 3 or 4 of the robberies. The Phoenix Police Department Robbery Detail
brought the case to the Crime Analysis Unit and asked for assistance in
predicting the next hit location and any information they could find on a
potential suspect. Phoenix crime analyst Karen Kontak worked on the case
throughout and played an important role in solving it.
Desired Result:
The desired result for the
investigators involved in this series was to be able to apprehend this suspect
and stop his robbery spree. The Crime Analysis
Unit staff wanted to provide a accurate prediction of the next date, time, day
of week, and possible store the suspect would hit next in the series. This would of course aide the investigators
in "staking out" the appropriate store or stores and catch the
suspect in the act. Investigators also wanted the CAU to search records
collected by the department for any persons driving a red Saturn or similar vehicle
to provide investigative leads in the case.
Methods
Used:
The
Crime Analysis Unit staff utilized ArcView 3.2a GIS software, CrimeStat
spatial data analysis software, and Microsoft Office suite of products to
analyze the data and create a bulletin predicting the next hit location
and date/time information. In
addition, an extension to ArcView called Crime Analysis Tools Version 2.0
was also used to complete the spatial analysis modeling for a probability
grid surface which combines statistical methods with intuitive thinking on
the crime analyst's part. The probability grid method (PGM) produces a tactical
analysis for a crime series that improves upon any single statistical
model or process currently available to crime analysts.
PGM allows the crime analyst to apply the commonly accepted methods
of spatial statistical analysis, generally available census and landuse
data, and his/her own experience and knowledge of crime series events to
make a prediction of a next crime in a series.
By being consistent in methodology and being able to apply
experience and intuition to the process, the crime analyst can narrow the
focus of the search for the "best guess" location where the next
crime will occur. This of
course has the same limitations all analysis of human nature confronts;
will the suspect continue to behave in the manner he has in the past?
In addition to the predictive PGM process, analysts used CrimeStat
to create a journey to crime surface and narrowed the list of potential
suspects from 355 to 54 by predicting the potential home address of the
offender.
Synopsis:
The
first analysis was completed the day prior to the suspect hitting his last
target. The analysis
predicted he might hit this target at the date and time the last robbery
in this series was committed. AT
the time, resources were not available to stake out this location and
other potential suspects were being followed.
During the last robbery, the suspect murdered a witness who tried
to stop him. This offense
occurred in Glendale and the Glendale Police Homicide unit was also
included in the analysis predicting the offender's next hit.
In addition, they were given a list of 8 individuals that had been
stopped driving a red Saturn, fit the general description of the offender,
and lived in the journey to crime area predicted using CrimeStat.
One of these individuals had a felony warrant for his arrest
stemming from a drive-by shooting in which a small caliber rifle was
believed to be used. The
suspect in the robbery series had used a 22 rifle for the first several
robberies and was intially dubbed the "22 rifle bandit."
Glendale and Phoenix police officers arrested the subject on the
felony warrant at his residence and found evidence of the robberies and
the homicide in his home. Case
closed by arrest.
Do you have any success stories in crime analysis to suggest... or, better yet,
to write up and send in?
A primary purpose of Success Stories is to salute selected crime analysts for work well done, but also, and more importantly, to describe what was done, how it was done, and the effects it accomplished. The most important intended mission of Success Stories is to help spread the word about methods and techniques of crime analysis which have been shown to work.
Please consider nominating someone for the honor, and, if you are not prepared to do the write-up yourself, let us know who might.
Disclaimer
The editorial staff of the Round Table can not verify submissions
made under the heading of success stories in crime analysis.
Accordingly, what is said here is a product merely of the submitter.
We see no reason for concern.
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