Applications in GIS: DC Crime

Assignment: Summarize Exploratory Spatial Data Analysis Techniques for Examining Urban Crime. http://www.geography.hunter.cuny.edu/~dougwill/CRIME/web_pdfs/intro_ESDA_murray-etal2001.pdf, Alan T Murry, Ingrid McGffog, John S Western, and Patrick Mullins.

This article provided an in depth detailing of “approaches for better understanding relationships of crime occurrences using a GIS and quantitative techniques”. The authors clearly explained the challenges of producing a quality GIS product (Examining Urban Crime): establishing what data is needed to meet the customer’s needs; determining how much data to put on the map while setting aside the basic map design theory; trying to sort through the wealth of data to be displayed by a GIS; and making a map or GIS product. The daunting goal of using a GIS in support of crime analysis is to produce products that tell the right story for the given audience.

I was most surprised to learn that with respect to the GIS there are no standard models for examining urban crime. There are many generalized assumptions that can be made but each must be tested for validity, accuracy, and precision. The panoply of data options combined with the ever growing GIS capabilities makes this kind of work quite exciting. GIS is still in its infancy and only in the last few years emerging and gaining acceptability in the study of crime events and the relationships to the physical surroundings.

Assignment: Complete the lab (4 maps total).

Deliverables:

4 Maps

A basemap of Washington D.C which includes:

Police Stations
Crimes
Roads
Census Block group

A map of police stations, locations of crime, recommendations for new substations.
A density map of burglaries, homicides, sex abuse crimes
GRADUATES ONLY: A map showing schools with the highest number of crimes nearby

1 Bar Graph showing total crimes (from deliverable 1 map).
Process Summary Worksheet (delivered to instructor)

Fill in tables
Answer questions 29 total for graduates
Explain your steps

Objectives: Upon completion of this lab students should be able to:

Create a map showing crime in urban areas.
Create graphs using ArcMap¡¦s Create Graph Wizard.
Analyze crime data for urban areas.

Law enforcement agencies increasingly are adopting GIS as a tool to improve public safety. Officials can decide where and how to allocate their resources once they pinpoint crime clusters. Spatial data helps police explore various factors contributing to crime.

In this exercise we used data from the nation’s capital to perform a crime analysis. The data comes from the DC Metropolitan Police Department and is compiled yearly into a database available for download at http://data.dc.gov/

Process summary
The DC Metropolitan Police Department has the technology available for crime analysis to allocate patrol resources efficiently. Imagine that you are a department GIS analyst who has been directed to investigate the following:

Crime patterns in proximity to police stations to determine if current patrols are effective or adjustments are necessary, such as reorganizing beats and building new substations.P
Patterns of aggravated assault, homicide, and theft-related crimes.
Patterns of when crimes are committed.

Process.

Step 1. Examine the data

Step 2. Create a process summary. This is where we explore the data. Look for value, consistency, and relevance. Once these are acceptable, then produce a base map which in this case show police stations, crimes, and roads. You will also see a graph showing the number of occurances of each type of offence.

Then put it all together by producing a map of the police stations and the locations of the crimes.

Step 3. Document the Map. Keep good descriptive names and steps along the way to avoid confusion. Try to make it easy for someone else step in with little or no prior knowledge. Or for people like me, make the names easy to remember and the storage locations logical.

Step 4. Set the environments. This is a key step since the real world data is comprised of formats and for our needs, a variety of coordinate systems and/or map projections. In this case I followed a series of 13 steps to get this done. Then saved it and called it Crime_Baseline. I would use this baseline through out the lab and save many, many steps and thus avoid mistakes

Deliverable 1: A basemap of Washington D.C. showing police stations, crimes, roads and census block groups. Include a graph of total crimes.