International Association of Crime Analysts (IACA) GIS Software Requirements for Crime Analysis Standards, Methods, & Technology (SMT) Committee White Paper 2012-01 June 2012 IACA SMT Committee Technology Chair: Matthew Harris, Crime Analyst, Sonoma County Sheriff's Office IACA SMT Committee Technology Members: Bryan Hill, Crime Analyst, Glendale Police Department Travis Taniguchi Ph.D., Senior Research Associate, Police Foundation Subject Matter Experts: Noah Fritz Ph.D., Crime Analysis Supervisor, San Diego County Sheriff's Office Wilpen Gorr Ph.D., Professor, Carnegie Mellon University James Lebeau Ph.D., Professor, Southern Illinois University Rebecca Paynich Ph.D., Professor, Curry College Joe Ryan, Crime Analysis Administrator, Jacksonville Sheriff's Office Suggested Citation: International Association of Crime Analysts. (2012). GIS Requirements for Crime Analysis (White Paper 2012-01). Overland Park, KS: Author. 1 About the IACA Standards, Methods, and Technology Committee Through the Standards, Methods, and Technology Committee (SMT), the International Association of Crime Analysts (IACA) is committed to a continuing process of professionalization through standards and knowledge development. In 2011, the IACA chartered the SMT Committee for the purpose of defining “analytical methodologies, technologies, and core concepts relevant to the profession of crime analysis.”i This document represents the first in a series of white papers produced by the SMT committee. The methodology for formulating the positions reflected in the white paper series includes 1) development of a draft paper through in-depth meetings and discussions of Subject Matter Expertsii, 2) review and feedback by the IACA Executive Board, 3) review and feedback from an independent editor with knowledge of crime analysis, and 4) review and feedback by IACA members facilitated through the IACA website (www.iaca.net). Any questions about this process can be directed to the chair of the SMT Committee at [email protected]. Overview As part of the efforts of the SMT committee of the IACA, this document has been prepared to address the requirements of mapping software otherwise referred to as geographic information systems (GIS) as used by law enforcement agencies for crime analysis. This document describes the current state of the art for GIS in crime analysis, and outlines functionality that is required of GIS software used for crime analysis. The primary intended use of this paper is to provide crime analysts, administrators, and other key decision-makers the fundamental software requirements for successful GIS in crime analysis. This document does not cover everything there is to know about GIS software or its uses, however it does explain some of the key applications and functionality an analyst will need when entering this world of geographic analysis. At the end of this paper, you will find a list of relevant literature covering these topics in detail and throughout you will find endnotes that point you directly to key readings in those publications on specific topics. We have also included a checklist that can be used as a starting point for evaluating GIS software (Appendix A). Comprehensive mapping systems are complex and the theoretical, statistical and practical assumptions that are made while using GIS are intricate. Crime analysts need adequate training in several key areas in order to use it effectively. GIS is among the largest application software packages in existence with many complex interfaces, tools, and work flows for spatial data processing, map making, and statistical analysis. Application of GIS in any business or government office is generally performed by professionals with specialized training. Many organizations use GIS occasionally for special projects, but GIS for crime analysis must become part of the fabric of police organizations. GIS, as a consistent and integrated piece of crime analysis and police operations, can be employed to produce regular daily reports, analyze information for special projects or issues, or to evaluate needs and assess results. Hence, GIS for police must be treated as a functional system, and not just a tool, that is fully integrated with an agency’s mission and operations. Recommendation 1, GIS training: Law Enforcement agencies wishing to make use of mapping software should ensure that their crime analysts are provided adequate GIS and crime analysis training with regular updates as technology changes. Crime analysts not only need to think about crime theory, they must also keep in mind user requirements and skill level, good data processing practices, and basics of map making, among many other factors. Municipal GIS departments, local schools and universities and the internet are good locations to look for cost 2 effective training programs. Importantly, when purchasing GIS software it is wise to invest in training from the vendor to ensure analysts and executives have a clear understanding and expectation of system capabilities. GIS for crime analysis has two identifiable sub categories: (1) data processing to obtain and prepare data, and (2) crime mapping and analysis itself to produces maps and information for different audiences. Figure 1 shows this typical framework for GIS software within a law enforcement agency. Data Processing An effective mapping system allows crime analysts to create permanent, standard map layersiii that are reused for data processing, analysis, and mapping as well as dynamic map layers that are continuously updated as time passes. Building and maintaining these map layers is a significant part of the workload of the crime analyst. Process 1: Create and Maintain Map Layers Process 1 includes building and maintaining the standard map layers (often called operational layers) that represent a police jurisdiction’s important features used in producing crime maps, such as streets and patrol district boundaries. The sources for these map layers generally come from data suppliers like federal government agencies such as the US Census Bureau and US Geological Survey; and state and local government agencies, such as engineering, zoning, and planning departments. Standard map layers may need to be transformed and enhanced for use by law enforcement agencies. For example, police zones and patrol areas may need to be created as aggregates of census tract boundary layers or digitized by tracing streets for boundaries, and the boundary of the jurisdiction may need to be extracted from a county map layer of places or minor civil divisions. As these boundaries change, the map layers will also need to be modified accordingly. 3 After the basemap for the crime analysis GIS is prepared and in use; there will be need for updates and additions. For example, streets generally need editing over time to make corrections, add missing data (where new streets were added for instance), and fix locations that do not get placed on the map (or geocode) correctly. Patrol zones are occasionally redrawn as crime patterns change or police budgets are tightened. At some point, additional features of a jurisdiction will be needed, such as boundaries and locations for zoning, census, and schools or crime-prone locations such as bars, ATM machines, and check cashing businesses. Recommendation 2, Geoprocessing, digitizing, and editing: Comprehensive GIS software needs to include geoprocessing tools including extracting and clipping features from larger collections, merging map layers, editing spatial and attribute features of map layers, heads-up digitizing using map layers such as streets for guidelines, and aggregating areas to create larger areas. These tools are necessary to create and maintain map layers. Occasionally analysts need to create new, unique data layers. It is currently difficult in GIS to create new data and attributes. For example, when an analyst needs to add point locations with attributes to a map they need to (1) create a new layer (2) add the layer to the map (3) start an edit session (allows the analyst to make a map layer) (4) add the necessary fields to the attribute table (the data behind the layer) (5) add the points, lines or polygons to the map (6) go into the table view to add the attributes (7) save the edit sessioniv. Recommendation 3, Streamlined data creation steps: Ideally GIS software should have a data creation tool and/or wizard that simplifies data creation steps. Crime Analysts work in tactical environments where they work with data in real time leaving little room for cumbersome multi-step processes. Process 2: Update Geocoded Files An important and central feature of GIS for crime analysis is that new incident data flow continuously from computer aided dispatch (CAD) and records management systems (RMS) into a crime analysis GIS. Handing such data requires more than merely adding data to the map; it requires complex data processing tools and procedures. The end results are master crime map layers that are the sole source for most crime mapping and analysis. These master map layers are organizational assets that require standardization and documentation. Additionally, the analyst must be able to store data about the data, called metadata (i.e.; when it was created, by whom, it’s frequency of updates etc.). Recommendation 4, Master map layers and aggregate data tables: The single sources of most crime mapping and analysis should be master map layers for crime incident points and space and time series data and these layers should be updated using good data management practices, and schedules. GIS software needs to allow for storage and updating of metadata. Data comes in a variety of formats such as DBF, CSV, and Excel tables as well as Open Database Connectivity (ODBC) connections to data in Oracle, SQL, and MS Access tables. An analyst must be able to get data from a table or ODBC connection to display within the GIS. GIS have several different possible formats for GIS data and your data needs to be converted to a supported format. A requirement of getting data into a GIS format is assigning geographic coordinates that identify where the data should be represented on the map.