GIS AND CRIME
MAPPING
Objectives:
Identify what is
crime mapping &
Recognize its
importance in Law
Enforcement
• What is crime mapping?
visuallize
Crime incident
patterns
Map: This likely refers to the geographic visualization of
crime incidents. By plotting crimes on a map, you can see
where they are occurring.
Visualize: This step involves creating different types of
visual representations of the crime data. This could include
charts, graphs, heatmaps, or other visual tools to identify
trends and distributions.
Analyze: This is the core step where you examine the
mapped and visualized data to look for patterns,
correlations, and insights. This might involve statistical
analysis, identifying hotspots, or understanding temporal
trends.
The central theme, highlighted in the large red box, is
"Crime incident patterns". This indicates that the overall
goal of this process is to identify and understand recurring
trends and distributions in crime data.
Key component
CompStat
policing strategy
5 key applications in crime
mapping
1. Thematic mapping- A thematic
map is a type of map that portrays
the geographic pattern of a
particular subject matter in a
particular area. This usually involves
the use of map symbols to visualize
selected properties of geographic
features that are not naturally
visible, such as temperature,
language or population.
• A thematic map uses symbols (like colors, dots, or
patterns) on top of a regular map to show things that
aren't naturally visible, such as:
– Where a lot of burglaries are happening (using
darker colors in those areas).
– The different types of crimes committed in
different neighborhoods (using different symbols
for each crime).
• So, for crime mapping, thematic maps help visualize
where different types or amounts of crime are
concentrated, making it easier to spot patterns and
understand what's happening geographically.
2. Non-graphical indicators
• These are global level
statistics indicating the
strength of spatial
autocorrelation, but not its
location. They compare
actual distributions of
crime incidents with
random distributions.
Unlike maps or visual representations, they
don't show where the clustering or dispersion
occurs, only how strong it is across the entire
study area.
Spatial Autocorrelation:
it asks: "Are things clustered together, dispersed,
or randomly distributed across space?" For
example, are high crime areas located near
other high crime areas?
Non-graphical indicators like Moran's I provide a
valuable overall assessment of spatial patterns.
In the law enforcement example, it helps the police
understand if crime incidents like burglaries are
generally clustered, dispersed, or random across
their jurisdiction.
While it doesn't pinpoint the exact locations of these
clusters (that's where graphical methods come in), it
provides a crucial first step in identifying the
presence and strength of spatial relationships,
informing broader strategic decisions about resource
allocation and crime prevention efforts.
3. Hot Spot Analysis
• Much of crime mapping is
devoted to detecting high-
crime density areas known as
Hot Spot. Hot Spot analysis
assist police in identifying
High-Crime areas, types of
crime being committed, and
the best way to respond.
Think of "hot spots" as places on a map where a
lot of crime happens.
Hot spot analysis is like using special tools and
techniques to find these areas with a high
concentration of crime incidents.
It helps the police see where crime is clustered so
they can focus their efforts there.
Instead of just looking at individual crime reports
scattered across the city, hot spot analysis helps
identify the neighborhoods or specific locations
that are experiencing more crime than others.
EXAMPLE
•Data Collection: They gather all the reported car
theft incidents from the past few months, including the
location (street address or intersection) and time of
each incident.
•Applying Hot Spot Analysis: They use a software or
statistical method (like kernel density estimation or
cluster analysis) to analyze this data. This method
looks for areas where many car thefts have occurred
close to each other.
•Visualizing the Results: The output is often a map
where areas with a high density of car thefts are
highlighted, perhaps with warmer colors like red or
orange, indicating "hot" areas. Areas with fewer car
thefts might be shown in cooler colors like blue or
green.
hot spot analysis helps the police move from
reacting to individual crimes to proactively
addressing areas with high crime
concentrations, making their efforts more
efficient and potentially preventing future
crimes.
It's about focusing resources where they are
most needed based on where crime is
happening most frequently.
4. Spatial Regression
• Is a statistical method use
to determine the
relationship between the
response variable and the
predictor variables taking
into account the linkages
between regions.
Imagine you're trying to figure out what factors
might cause crime in different neighborhoods.
Regular statistical methods can tell you if, for
example, poverty is linked to higher crime rates.
However, they often ignore the fact that
neighborhoods aren't isolated islands. What
happens in one area can influence what
happens in nearby areas.
Spatial regression is a special type of statistical
analysis that not only looks at the relationship
between a crime rate (the response variable)
and other factors (like poverty, unemployment,
number of liquor stores - the predictor
variables) but also considers how crime or these
factors in neighboring areas might be related. It
acknowledges that things are often connected
across space.
spatial regression helps law enforcement go
beyond simply looking at factors within a
specific area and understand how crime and
its causes are interconnected across
geographic space, leading to more effective
and targeted crime prevention strategies. It
acknowledges that crime doesn't happen in a
vacuum and that location matters in more
ways than one.
5. Geographic profiling
• Is a crime analysis
technique that uses the
locations of a connected
series of crime sites to
determine the most
probable area of offender
residence.
Imagine a detective investigating a series of
similar crimes (like burglaries or assaults) that
have happened in different locations.
Geographic profiling is like using a map and the
patterns of these crime locations to guess where
the offender most likely lives. It's based on the
idea that criminals often operate within a
certain range of their home or a familiar base.
By analyzing the "where" of the crimes,
investigators can narrow down the "where" of
the criminal's residence.
Geographic profiling provides law
enforcement with a valuable tool to prioritize
their investigative efforts by statistically
predicting the most probable area of
offender residence based on the spatial
pattern of their crimes. It helps narrow the
search and makes investigations more
efficient, especially in cases involving serial
offenders.
It's about using the geography of crime to
understand the geography of the criminal.
DIFFERENCES
Geographical profiling predicts an offender's
residence based on crime locations
Thematic mapping visualizes crime data
geographically using symbols or colors
Non-graphical indicators statistically describe
spatial crime patterns
Hotspot analysis identifies crime
concentration area
Spatial regression models the relationships
between crime and various spatial factors.
Types of crime
mapping
1. Manual Pin Mapping
Imagine a physical map of a city or region hanging
on a wall in a police station.
Manual pin mapping involves taking physical pins
of different colors or shapes and sticking them
onto the map to represent different types of
crimes or incidents that have occurred at specific
locations.
Each pin marks a single event.
By looking at the pattern of pins on the map,
investigators can visually identify areas where
certain types of crimes are happening more
frequently or if there are any emerging clusters.
It's a straightforward way to see the spatial
distribution of crime.
2. Computer Mapping
• A computer map was been
taken from an internet
mapping program where
an address is entered and
a map of the surrounding
area appears with a pin to
locate the address.
Think of computer mapping as the digital and
much more powerful version of the manual pin
map we just talked about. Instead of sticking
physical pins on a paper map, law enforcement
uses computer software to display crime data on
digital maps. They can enter addresses or
locations of crimes into the software, and it will
place digital "pins" or markers on the map.
The big advantage of computer mapping is that
it's much more flexible and allows for a lot more
information and analysis than a physical pin
map. You can easily change what you're looking
at, zoom in and out, layer different types of
information, and even perform automated
analysis to find patterns.
3. The geographic
information system (GIS)
• GIS is a set of
computer-based tools
that allow a person to
modify, visualize, query
and analyse geographic
and tabular data.
Think of GIS as a super-powered, smart
computer mapping system. It's not just about
showing locations on a map; it's a whole set of
tools that lets you work with different kinds of
information that are linked to specific places.
You can put various layers of data onto a map,
like crime locations, roads, demographics
(information about people), buildings, and much
more.
The good thing about GIS is that it allows you to
ask questions about this data and analyze how
things are related geographically. You can
visualize patterns, find relationships between
different factors, and even predict what might
happen in the future based on location. It's like
having a smart map that can answer questions
and show you connections you might not see
just by looking at a list or a simple map.
GEOGHRAPHIC INFORMATION
SYSTEM
• It is a computer system that
analyses and displays
geographically referenced
information .
• It is used to visualize,
analyse, and interpret
geographic data.
• How helpful is GIS in crime mapping?
Why GIS is important in
law enforcement?
• geographical profiling of
offenders,
• help determine where an
offender may live,
particularly in serial
cases.
