GIS

GIS is an acronym for Geographic Information System, a type of computer software that stores, manipulates, and displays maps and other spatial data. In forensic science , GIS software can be used to display and analyze patterns in maps showing crime scene locations, transportation routes, and potentially important forensic information such as bedrock or soil types. Some proponents have expanded the original definition of GIS to Geographic Information Science in reference to the body of knowledge about the techniques and applications of GIS software in addition to the software itself, but this article uses the original definition.

The October 2002 sniper shootings around Washington, D.C., are a high-profile example of a criminal case in which GIS software was used as a forensic tool. As the shootings occurred, detailed maps of the shooting locations were created and concentric circles were drawn at 1/4 and 1/2 mi (0.4 and 0.8 km) radii around the location of each incident. This allowed investigators to inventory buildings and other features that may have hidden the snipers, identify roads that the snipers may have used to arrive at or leave the scenes, and analyze similarities and differences among the shooting locations. At the time that two suspects were arrested, there were plans to expand the use of GIS to quantify the ease of access to each crime scene, analyze demographic and economic information about the areas in which the shootings occurred, and create three dimensional renderings of the crime scenes in order to identify similarities and perhaps predict the likely locations of future shootings. One of the difficulties encountered in this case was that the shootings occurred in different counties and states, and much effort was required to combine data from the different jurisdictions. Similar techniques have been used to solve serial rape cases in several large cities.

The use of geographic information to help identify suspects is known as geographic profiling . Although it is sometimes portrayed in the popular media as a highly developed discipline, geographic profiling is an imperfect practice that is continually evolving. Geographic profiling computer programs available in 2005 were based upon the results of research conducted in the 1980s and 1990s. The results suggested that most offenders commit crimes close to their homes; crime patterns follow a distance-decay function (the number of crimes committed decreases with distance from the offender's home); juvenile crimes are more highly clustered than adult crimes (because juveniles lack easy access to transportation); and the distance traveled varies according to the kind of crime. The output of geographic profiling programs consists of so-called hit score maps that use colored contour maps or three–dimensional surface maps to indicate the likelihood that a perpetrator lives in a certain area. Hit score maps can be combined with additional information, for example the addresses of known offenders or other suspects, and displayed using GIS software. Because of the amount of information required, geographic profiling works best in large cities where many crimes are committed. It can also require officials to recognize that a series of crimes are related and have likely been committed by the same person. Geographic profiling may fail in cases where a suspect travels great distances to commit crimes.

GIS software is also used by many agencies for so-called hot spot analysis, in which the locations of crimes such as murder, burglary, and auto theft are plotted on maps. Specialized computer programs available to law enforcement agencies can then be used to find clusters of crime scenes, or hot spots, that may help to identify areas for undercover operations or increased police patrols. Although the two share some similarities, hot spot analysis is different from geographic profiling. Hot spot analysis identifies locations in which crimes are committed whereas a geographic profile is intended to identify the person committing the crimes that, like hit score maps, can be linked to the home or work addresses of suspects using GIS software. GIS analysts can then add other information such as the location of forested areas that might provide an avenue of escape or the occurrence of soil identical to samples obtained from a suspect's shoes. Some jurisdictions make crime location data available over the Internet, allowing citizens to interactively query databases and produce maps of reported crimes or the registered addresses of convicted sex offenders.

When combined with global positioning system (GPS) receivers and transmitters, GIS software can be used to track the movements of criminals released on parole or probation to determine if they are related to newly reported crimes. GPS receivers installed in police vehicles can likewise transmit their locations and help to more efficiently dispatch law enforcement officials in the minutes after a crime has been committed. In 2005, some transit police in San Francisco were equipped with wireless personal digital assistants (PDAs) that allowed them to use GIS information while on foot or in trains and laptop computers for use in patrol cars.

see also Computer modeling; Crime scene investigation; Geology; Remote sensing.

GIS

█ K. LEE LERNER

GIS is the common abbreviation for Geographic Information Systems, a powerful and widely used computer database and software program that allows scientists to link geographically referenced information related to any number of variables to a map of a geographical area. GIS allows its users to analyze and display data using digitized maps. In addition, GIS can generate maps and tables useful to a wide-range of applications involving planning and decision-making. GIS programs allow the rapid storage, manipulation, and correlation of geographically referenced data (i.e., data tied to a particular point or latitude and longitude intersection on a map).

In addition to scientific studies, by 2003, GIS programs were in wide use in a number of emergency support agencies and systems (e.g., the Federal Emergency Management Agency (FEMA)).

GIS programs allow scientists to layer information so that different combinations of data plots can be assigned to the same defined area. GIS also allows users to manipulate data plots to predict changes or to interpret the evolution of historical data.

GIS maps are able to convey the same information as conventional maps, including the locations of rivers, roads, topographical features, and geopolitical information (e.g., location of cites, political boundaries, etc.). In addition, to conventional map features, GIS offers geologists, geographers, and other scholars the opportunity to selectively overlay data tied to geographic position. By overlaying different sets of data, scientists can look for points or patterns of correspondence. For example, rainfall data can be layered over another data layer describing terrain features. Over these layers, another layer data representing soil contamination data might be used to identify sources of pollution. In many cases, the identification of data correspondence spurs additional study for potential causal relationships.

GIS software data plots (e.g., sets of data describing roads, elevations, stream beds, etc.) are arranged in layers that can be selectively turned on or turned off.

NASA engineers and teams of other scientists—including researchers and undergraduates from Stephen F. Austin University in Nacogdoches, Texas—employed GIS mapping to map remains found after the break up of the space shuttle Columbia in January 2003. Debris field maps helped narrow search patterns and—by linking the location of debris—allowed engineers and investigators to reconstruct critical elements of the disaster sequence. GPS data were used to construct the debris maps and to provide accurate representations of the retrogressive pattern of debris impacts.

GIS technology can also aid epidemiologists in tracking diseases and would be instrumental in the early identification of patterns of disease that could reveal a bioterrorist attack.

█ FURTHER READING:

BOOKS:

Rigaux, P. et al. Spatial Databases: With Application to GIS. Morgan Kaufmann, 2001.

Steede-Terry, K. Integrating GIS and the Global Positioning System. ESRI Press, 2000.

SEE ALSO

Forensic Geology in Military or Intelligence Operations
Geologic and Topographical Influences on Military and Intelligence Operations
Geospatial Imagery

GIS

GIS is the common abbreviation for geographic information systems, a powerful and widely used computer database and software program that allows scientists to link geographically referenced information related to any number of variables to a map of a geographical area. GIS allows its users to analyze and display data using digitized maps. In addition, GIS can generate maps and tables useful to a wide-range of applications involving planning and decision-making. GIS programs allow the rapid storage, manipulation, and correlation of geographically referenced data (i.e., data tied to a particular point or latitude and longitude intersection on a map).

In addition to scientific studies, by 2003, GIS programs were in wide use in a number of emergency support agencies and systems (e.g., the Federal Emergency Management Agency [FEMA]). Broad in scope, GIS is has also attained a significant role in business and marketing decisions.

GIS programs allow scientists to layer information so that different combinations of data plots can be assigned to the same defined area. GIS also allows users to manipulate data plots to predict changes or to interpret the evolution of historical data.

GIS maps are able to convey the same information as conventional maps, including the locations of rivers , roads, topographical features, and geopolitical information (e.g., location of cites, political boundaries, etc.). In addition, to conventional map features, GIS offers geologists, geographers, and other scholars the opportunity to selectively overlay data tied to geographic position. By overlaying different sets of data, scientists can look for points or patterns of correspondence. For example, rainfall data can be layered over another data layer describing terrain features. Over these layers, another layer data representing soil contamination data might be used to identify sources of pollution . In many cases, the identification of data correspondence spurs additional study for potential causal relationships.

GIS software data plots (e.g., sets of data describing roads, elevations, stream beds, etc.) are arranged in layers that be selectively turned on or turned off.

In addition to scientific studies, GIS technology is increasingly used in resource management. When tied in with GPS data, GIS provides very accurate mapping. GIS provides, for example, powerful data correlation between pollution patterns monitored at specific points and wildlife population changes monitored by GPS tracking tags.

NASA engineers and teams of other scientists—including researchers and undergraduates from Stephen F. Austin University in Nacogdoches, Texas—employed GIS mapping to map remain found in after the break up of the space shuttle Columbia in January 2003. Debris field maps helped narrow search patterns and, by linking the location of debris, allow engineers and investigators to reconstruct critical elements of the disaster sequence. GPS data was used to construct the debris maps and to provide accurate representations of the retrogressive pattern of debris impacts.

See also Archeological mapping; Cartography; Geologic map.

Gis

GIS is the common abbreviation for Geographic Information Systems, a powerful and widely used computer software program that allows scientists to link geographically referenced information related to any number of variables to a map of a geographical area .

GIS programs allow scientists to layer information so that different combinations of data plots can be assigned to the same defined area. GIS also allows scientists to manipulate data plots to predict changes or to interpret the evolution of historical data.

GIS maps are able to convey the same information as conventional maps, including the locations of rivers , roads, topographical features, and geopolitical information (e.g., location of cites, political boundaries, etc.).

In addition to conventional map features, GIS offers geologists, geographers, and other scholars the opportunity to selectively overlay data tied to geographic position. By over-laying different sets of data, scientists can look for points or patterns of correspondence. For example, rainfall data can be layered over another data layer describing terrain features. Over these layers, another layer data representing soil contamination data might be used to identify sources of pollution. In many cases, the identification of data correspondence spurs additional study for potential causal relationships.

GIS software data plots (e.g., sets of data describing roads, elevations, stream beds, etc.) are arranged in layers that be selectively turned on or turned off.

In addition to scientific studies, GIS technology is increasingly used in emergency planning and resource management. When tied in with GPS data, GIS provides very accurate mapping. GIS provides, for example, powerful data correlation between pollution patterns monitored at specific points and wildlife population changes monitored by GPS tracking tags.

Broad in scope, GIS is becoming more widely used in business and marketing studies.

See also Archeological mapping; Area; Cartography

GIS

GIS is the common abbreviation for geographic information systems, a powerful and widely used computer database and software program that allows scientists to link geographically referenced information related to any number of variables to a map of a geographical area. GIS allows its users to analyze and display data using digitized maps. In addition, GIS can generate maps and tables useful to a wide-range of applications involving planning and decision-making. GIS programs allow the rapid storage, manipulation, and correlation of geographically referenced data (i.e., data tied to a particular point or latitude and longitude intersection on a map).

GIS has expanded from use in a number of emergency support agencies and systems such as the Federal Emergency Management Agency (FEMA) and in military conflict to widespread general use. Many car and truck models built in 2006 come with GIS as a navigational aid, for example. Portable GIS units are available that can be used for directional aid while walking, and even to help a golfer in their club selection by determining the distance remaining between the ball and the hole.

GIS maps are able to convey the same information as conventional maps, including the locations of rivers, roads, topographical features, and information including location of cites and political boundaries. Different types of information can be incorporated into a GIS image. For example, rainfall data can be expressed along with data describing terrain features and soil contamination data to identify sources of pollution.

In a poignant use of the technology, GIS mapping was used to map remains after the break up of the space shuttle Columbia in January 2003. Debris field maps helped narrow search patterns and by linking the location of debris allow engineers and investigators to reconstruct the disaster.