Fundamentals of Crime Mapping Chapter 1 Instructor name here
Dec 08, 2014
Fundamentals of Crime Mapping
Chapter 1
Instructor name here
General class instructions here
Class basics and introductions
ArcGIS◦ “GIS Tutorial”
ESRI (www.esri.com) 180 day copy of ArcGIS
Alternative: “Getting to Know ArcGIS for Version 9” http://
gis.esri.com/esripress/display/index.cfm?fuseaction=display&websiteID=144&moduleID=0
◦ Get 60 day Evaluation copy from ESRI Website (order early)
◦ http://www.esri.com/software/arcgis/arcview/eval/evaluate.html
◦ Get 1 year Student license from ESRI for $100.00
◦ http://www.esri.com/industries/university/education/sitelic.html#individual
Additional ArcGIS Software
CrimeStat III ◦ http://www.icpsr.umich.edu/CRIMESTAT/◦ Manual is also very good reference manual for
spatial statistics
Additional CrimeStat III Software
The more you desire to learn, the more you learn
Practice, practice, practice
Develop a thick skin◦ Your first maps are going to be awful, listen to constructive criticism and don’t
take it too personally
Don’t give away this new skill◦ Practice and keep up to date with it◦ Will reward you in many professions as an additional skill
that is marketable
More class introduction
Introduction to Crime Mapping
Victims Suspects Environment Time
◦ Who, What, When, Where, Why and How?
Criminal Event
The study of crime and criminal behavior◦ No generally accepted single theory that explains
the existence of crime in a society◦ Consensus perspectives
Approach crime as a normal and healthy part of any society
◦ Conflict perspectives Argue that crime is the result of group conflict and
unequal distributions of power
Criminology
Macro◦ Make assumptions about societal-level variables,
including the structure of government and the economy and how these variables impact crime rates within a society
Micro◦ Make assumptions about individual characteristics
(IQ, mental state, temperament, biological characteristics, and personal finances, for example) and how they influence a person’s decision to commit a crime
Levels of application
Time and Place AsAspects of Criminal Event
TimeSuspect
Environment/Place
Victim
Economic composition of a community contributes to crime by affecting neighborhood order
Higher juvenile delinquency rates tended to cluster in certain neighborhoods within urban areas
Poverty and residential instability,◦ Impacted both the physical appearance and the social structure of
the neighborhood itself High population density High population mobility Higher numbers of suitable targets Motivated offenders coexisted with little or no guardianship Produces higher rates of crime Higher rates of crime regardless of who lived there The area, not the people, is criminogenic
Social Disorganization Theory
Three very basic premises◦ Environmental Criminology
Environment can affect crime Target rich environments
◦ Routine Activity Theory We all have routines, in our down time, we commit crime Mental maps and nodes, paths, awareness space
◦ Rational Choice Theory Suspects plan to some degree their crimes If we understand the reason for the choices, we can
understand and forecast where the offender goes next Crime Pattern Theory is a combination of all of
these
Criminology
Two Good Web References◦ http://www.geo.hunter.cuny.edu/capse/projects/nij/crime_
bib1.html◦ http://en.wikipedia.org/wiki/Crime_mapping
References
Certain locations can be crime attractors (Crime pattern theory)◦ Bank ATM◦ Sports Venues (Coyotes Stadium, etc)
More potential victims Security
◦ Design of building or path through makes cover and concealment available to suspect and disadvantage to victim
Ease of escape◦ Ability to commit crime and leave the scene without
detection◦ Darkness◦ Closeness of a freeway, etc.
Crime Prevention through Environmental Design (CPTED)
Motivated offender Suitable target Absence of a capable guardian
Routine Activities Theory
Mental Maps◦ If you had to draw your world right now, what would it
look like?◦ Where do you live, work, play? (nodes)◦ How do you get back and forth between these places?
(Paths)◦ The areas between nodes and paths that are known to
you because of your routine activities, are your “awareness spaces”
◦ I drive to work everyday and see construction and say, “Wow, it sure is growing out this way”
The person with a criminal intent says, “Wow, look at all the construction equipment that isn’t locked up around here!”
◦ Can be a great interview technique, because all maps are “true!”
Mental Maps
Routine Activities Theory Analysis Triangle
Family,Probation Officer
Home Owners,Teachers
Police,Private Security
Relation to Crime Mapping
Nodes Paths Awareness Space Escape Routes Geography of
Victimology
• What does this offender’s nodes maybe tell you about him/her?
Journey to Crime Result
Intelligence Application
Theory should power all mapping and analysis projects◦ Think about
Suspect’s search patterns Least effort Mixed scanning
Find an area then find a target Bank ATM, Sports Arena, Big Event, Mall
Awareness spaces Knowledge ComfortRoutines and rhythms Obligatory time (work etc.) Discretionary time (Crimes occur now)
Considerations
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Marauder Vs. Commuter
Focus on Crime Theory:
Marauder orPoacher
CommuterOr Hunter
We are all human beings and each of us uses some thought process to make decisions
Criminals and “normal” people are fundamentally the same
We make decisions on where to commit our crime through:◦ What is the benefit I receive?◦ Is it relatively safe?◦ Can I escape easily?◦ Number of potential witnesses to my crime?
Identification of myself by police and others
Rational Choice Theory
Hypothesis testing
should be an
everyday part of crime
analysis
Crime analysis◦ Focus on events
Administrative Operational or Police Operations Analysis
Strategic Tactical
Criminal intelligence analysis◦ Focus on people◦ Organized criminal activity and seeks to link people, events, and
property Investigative analysis
◦ Focus on investigation of specific crimes◦ Victim characteristics and elements of crime scenes are studied
to discover patterns that link related crimes together◦ Investigative support
Categories of Crime Analysis
“is the systematic study of crime and disorder problems as well as other police-related issues—including sociodemographic, spatial, and temporal factors—to assist the police in criminal apprehension, crime and disorder reduction, crime prevention, and evaluation” (Boba, 2005, p. 6)
“focused on the study of criminal incidents; the identification of patterns, trends, and problems; and the dissemination of information that helps a police agency develop tactics and strategies to solve patterns, trends, and problems” (Bruce, 2004, p. 15)
Definitions of Analysis
Common Crime Analysis Goals
Provide information that is fast, reliable and accurate (data quality)
Improve administrative reports where needed
Improve strategic analysis efforts for better decision making
Begin proactive analysis of several crime types that can be impacted by crime analysis efforts
Involves the presentation of key findings of crime research and analysis to audiences within law enforcement, local government, and citizenry based on legal, political, and practical concerns including:◦ A report on demographic changes in the jurisdiction◦ Miscellaneous crime statistics to support grant
applications◦ Preparation of Uniform Crime Report (UCR) or
Incident-Based Reporting System◦ Hotspot, pin, or reference maps for the jurisdiction
Administrative Analysis
Administrative Analysis Objectives
Assist in general reporting Improve UCR coding processes by
reviewing coded reports for accuracy Suggest improvements to the
management system when needed Produce reports and data in a timely
manner Provide general hot spot and crime
distribution maps and reports on an ad-hoc basis
Do staffing studies
Administrative (bean counting)◦ Reference maps◦ Hot spot or hot area maps◦ Graduated symbol maps◦ Pin maps
Larger geography area Longer time periods Less specific focus Multi-layer geoprocessing (thematic
mapping)◦ Using several layers of data to make one final map◦ Redistricting is an example
Administrative Maps
Involves the study of crime and other law enforcement issues to identify long-standing patterns of crime and other problems and to assess police responses to these problems (Boba, 2005)
Typically, this analysis involves collecting a great deal of information about criminal events. In addition, “helping agencies to identify root causes of crime problems and develop creative problem-solving strategies to reduce crime” is a key goal in strategic crime analysis (IACA)
Strategic Analysis
Strategic Analysis Objectives
Create hot spot maps by various geographic areas and boundaries◦ Do time comparison studies
Create reports that are easily read and explain general date, time, and day of week distributions of crime in specific geographic areas identified in the administrative process
Find “thresholds” of activity in specific geographic areas to provide weekly or monthly strategic battle plans to all units of the department
Create new reports and processes needed to support this function throughout the department
Database support
Strategic◦ Hotspot maps◦ Graduated symbol maps◦ Pin maps (limited)◦ Multi-layer, thematic, geoprocessing
Recurring or significant problem you are trying to find or isolate
Smaller geographic area Shorter time period More specific focus Problem-solving or intelligence-led policing
workhorse
Strategic Maps
Examines recent criminal events and potential criminal activity by analyzing how, when, and where the events occur to establish patterns and series, identify leads or suspects, and to clear cases (Boba, 2005)
Tactical Analysis
Tactical Analysis Objectives
Find trends, clusters, patterns, sprees and series of criminal activity through proactive review of reports.◦ Identify the next day of week, time of day, and
likely date of a new crime by the same offender (s) (Statistical Analysis)
◦ Provide additional investigative data from police files and resources on similar crimes or M.O. (Database Searches)
◦ Identify the likely location of a new crime in a series or trend (like, ellipses, rectangles, probability grid analysis)
◦ Identify the likely home address location or anchor point for an offender and provide person information to investigative units for consideration (journey to crime)
◦ Repeat as needed
Tactical◦ Hot spot maps◦ Graduated point maps◦ Pin Maps◦ Thematic mapping
Waiting for the next incident to happen Predictions for new hit Journey to crime analysis
◦ Very specific focus◦ Short time spans analyzed◦ Very limited to some range of geography
Tactical maps
Benefits of Crime Analysis
More data is available to you◦ Become “intimate” with the data
Data problems can be identified and corrected
Excellent tool for goal planning and completion and applying the SARA model to problems:◦Collect, collate, analyze, disseminate, and
EVALUATE vs. S.A.R.A.
Geographic Information Systems have developed over the past 30 years
◦ First crime map in early 1900’s in New York◦ First computerized crime map in 1960’s
Canada led the way◦ More common use in late 1980’s, early 90’s
GIS use has increased dramatically in the past 5-10 years, however may still be underused in some police departments
2002 ACJC study, only 15% of AZ agencies using it
ACJC Crime Mapping in Arizona 2002.pdf
GIS in history
The “SYSTEM” part of GIS could be used to describe all of the diverse assortment of data that a normal police department collects during day to day operations
◦ Geographic data (incident locations, home addresses, etc)◦ Data that can be tied to the geographic data (person’s DOB,
Vehicle make, property, M.O., etc.) A GIS can assist police with
◦ optimizing limited resources◦ directing enforcement activities to needed areas◦ streamlining and improving business processes◦ identifying critical information problems within datasets
collected and maintained.◦ Quality control
With this increase in the amount of data available to decision makers, we have to be able to make sense of all of this data.
GIS defined
In the business community this is often described as “business intelligence” or the process of taking the bits and pieces of data we collect everyday,
Ordering it and organizing it so that it makes sense and provides information, to assist other analysts, administrators, detectives, and patrol officers
To develop knowledge to prevent crimes, catch criminals, or enhance public safety.
Business Intelligence
My audience determines what type of map I produce and that you will have many different people and purposes within the audiences you will address as a crime analyst
Key element
Has increased (or can increase) efficiency in the data collection processes
◦ Easy to do, so more data is used◦ When you are mapping data, you often find the “big”
accuracy or reliability problems with your data collection systems and can make recommendations to improve them
◦ Quality assurance measures can be identified Promotes by it’s sheer nature – DATA SHARING
◦ GIS the common language
GIS Rewards
Saves time for your agency when used correctly
Saves money by understanding the processes or the work flow of the data you will use
GIS Rewards
You will learn more information about crime in your jurisdiction faster and become the resident “expert” in data, software, and often hardware
GIS Rewards (not always a good thing)
You will develop new partnerships with people◦ Your own city (IT staff, Engineering, Utilities, Planning,
etc.)◦ In our county (IT Staff, GIS section, Elections,
Association of Governments, etc.)◦ Between other law enforcement agencies
Data sharing projects and cooperative grant processes◦ In your state and with the federal government
Homeland security Grants Geospatial One-stop web sites
GIS Rewards
With GIS, we deal with several different types of data. In the ArcMap application we deal mostly with 4 basic data formats:◦ Vector
Points Lines (sometimes called Arcs) Polygons
◦ Raster Image
The Software for GIS
Points◦ incidents or events
Radio calls Crimes
◦ physical features Police stations Schools Evidence found
The GIS Software
Lines (sometimes called Arcs)◦ Streets◦ Knows start and end◦ Can be used for routing◦ Distances between things (length)◦ Knows what’s on the right or left◦ Boundary lines
GIS Software
Polygons◦ Are bounded by limits of box◦ Knows what is within and what borders itself◦ Aggregation container◦ Knows it’s AREA
GIS Software
Raster vs. Vector data◦ Points, lines and polygons are Vector data with
aggregation or not Discrete data (a line stitched on to a blanket)
◦ Raster data is like a weather map Satellite photos, radar, aerial images Continuous data (the entire blanket)
GIS Software
Raster or Vector?
Raster or Vector?
Raster or Vector?
“A computerized mapping system that allows a police department to analyze geographic and related data collected during the course of police activities, to provide insight into better crime fighting strategies, community based policing program evaluation, administrative, strategic, and tactical planning and intervention activities, predicting suspect behavior and patterns in active investigations, and to utilize the data more effectively through graphic display of data in a easy to understand “map” format, as well as develop strategies to guarantee accurate data collection to achieve sound analysis products for decision making processes, across all units within a police department.”
One Law Enforcement GIS Definition
IACA Vendor List◦ http://www.iaca.net/Software.asp
Crime Mapping (NIJ Maps)◦ http://www.ojp.usdoj.gov/nij/maps/software.html
IACA (International Association of Crime Analysts)◦ www.IACA.net
AACA (Arizona Association of Crime Analysts)◦ http://www.aacaonline.org/
And many many more listed in the textbook
Resources
Projections
The method used to transfer locations on the Earth’s surface to a flat map is called projection.
Projections…3D to 2D
There are hundreds of mathematical calculations to make the data at some point on the earth’s surface the “most” accurate.
The earth is not perfectly round (spheroid)◦ Hills and valleys, etc
All map projections distort the surface in some fashion◦ Area ◦ Shape ◦ Direction ◦ Bearing ◦ Distance ◦ Scale
Projections…3D to 2D
Common Projection for USA is Universal Transverse Mercator◦ Latitude and Longitude lines◦ State plane coordinate system derived from this
projection for better accuracy Nad 1983, Fips 0202 Az Central – Maricopa and other counties
Most states have 3 zones (FIPS zones) International feet
Measurement units
Projections…3D to 2D
Important to know projection to share data Important to measure correctly ArcGIS Shapefile creates a .PRJ file which
stores the projection information so it can be used with other data
I sharing data:◦ Provide complete projection
State Plane Coordinate System, Nad 1983, Fips 0202, Az Central, Intl Feet (or meters, feet, etc)
Projections…3D to 2D
ArcGIS –ArcView ArcMap Level
Table of Contents
Toolbars and Menus
Menu Bar or Menu Items
Map DisplayMap WorkspaceStart-up
Dialog
ToolBox
GIS Software with 3 levels◦ ArcInfo◦ Arc Editor◦ ArcMap (what we have)
Made by ESRI◦ www.esri.com
Initial steep learning curve Can do just about anything and only
limited by your imagination
The ArcGIS Project
The ArcGIS Project
Map Display
Menu Bar (Activate by clicking and
choosing item)
TOC Tabs (Display, Data Source, and Selected records
views)
Table of Contents
The ArcGIS Project
Map Display
Checked, or Turned On or Visible in Map
Display
Display tab – shows you what layers are available in the data
frame and can be viewed on the map display area
Table of Contents
Highlighted or “Selected”
The ArcGIS Project
Map Display
File Directory Path
Source – gives you the file location for the data in the
project
Table of Contents
The ArcGIS Project
Map Display
Selectable and records selected
Selection – let’s you choose which themes can have records
selected, and which themes have records selected in them -bolded
and number of records in “()”
Table of Contents
Not Selectable
The ArcGIS Project
Map Display
Themes or layers
Data Frame Standard
toolbar
Layout toolbar
View ToolsTable of Contents
The ArcGIS Project
Map Display
Right Click on Data frame to get data
frame properties menu
Table of Contents
The ArcGIS Project
Map Display
Right click on theme name to get Layer Properties menu
Table of Contents
The ArcGIS Project
Map Display
Symbology Tab Allows us to make
changes to how the data is displayed
and classified
The ArcGIS Project
Definition query tab allows us to choose what data we see
The ArcGIS Project
Label tab let’s us label just about anything on the map automatically
and we have more choices and options than we can shake a
stick at
The ArcGIS Project
Map display View
layout View
Standard tools active – Layout tools not active
Layout tools active – Standard tools also active
You need to make sure you keep the layout tools and the
standard tools separate in your mind as they work on
the data differently
The ArcGIS Project
Map Display
Arc Toolbox
Add Data
Table of Contents
The ArcGIS Project
Allows us to add data from a variety of sources:• GIS Layers• Tables• Images• ODBC and OLE DB Connections to databases
The ArcGIS Project
Map DisplayTable of Contents
Arc Toolbox
The ArcGIS Project
Map Display
Arc Catalog Button
Table of Contents
The ArcGIS Project
New program opens – File Information, data Structure
and metadataLibrary of sorts
You can manage your data, search and find data, view data, and add metadata (data about data) in Arc
Catalog. You can also create new data and drag and drop data into ArcGIS from Arc
Catalog
Querying Tables in ArcMap
Be sure to use complete SQL structure:◦ [FieldName] = ‘Something’◦ Field, operator, and Value
Querying Data in ArcCatalogue
Useful for finding data
that meet your
geographic boundaries or contain
some element
you need
Practice Makes Useful Use the exercises in class and practice,
practice, practice!
Practice Makes Perfect You WILL find the light at the end of the
tunnel
Definitions and Terms
Crime Types Trend – A crime trend is the occurrence of similar
offenses in a geographic area that have increased or decreased within a given time period and this can be measured.
Pattern – A crime pattern is the occurrence of similar offenses in a geographic area that may or may not be committed by the same suspect or suspects.
Cluster – A crime cluster is the occurrence of similar offenses within close proximity to each other potentially leading to identification of a crime series or not.
Series – A crime series is the occurrence of offenses showing evidence that the same suspect or suspects has committed the crimes. This is verified through similar MO’s or suspect descriptions.
Spree – A crime spree is a set of crimes committed sequentially by the same suspect or suspects over a short period time.
Definitions and Terms
General Terms Hot Spot – An area that has been identified to have
more crime than another area or has a higher “density” of crimes.
Density – Density is a term applied to geographic elements and their relationship to each other. A location or group of crimes is considered more dense as their numbers increase and the proximity to another location or crime is reduced.
Threshold Analysis – A product used as an early warning system for crimes in a specific geographic area to determine if the total numbers are higher or lower than the a previous, equal, time period.
Spatial Analysis (Geoprocessing) – The science of using geographic elements and their relationship to other geographic elements to analyze crime and crime associations.
GIS – Geographic Information Systems. Also known as computer mapping.
Definitions and Terms
General Terms Frequency Distribution – A listing of numbers or scores
in ascending or descending order. Mean – The mathematical average of a set of numbers. Median – The middle score in a distribution. Mode – The most frequent score in a distribution. Standard Deviation – This is the average of the
differences between scores in a frequency distribution yielding to a normal distribution (bell-shaped curve).
Central Tendency – A term used to describe the proximity of a score in a distribution to the mean of the same distribution.