Dr. R. Sahu
Indian Institute of Information Technology & Management, Gwalior
Telephone Numbers: 0751-2449 804, 9893198467
Room No 352, Boys Hostel
Indian Institute of Information Technology & Management, Gwalior
Telephone Numbers: 0751-2449 804, 9893198467
Prior to the computers the law enforcing authorities had a tough job controlling the crime, they had a very limited resources compared to resources which modern crime fighters have today. Computers have really changed the dynamics of crime fighting; crime fighters are now armed with latest technology which helps them to nab the culprits in no time.
Crime is a human phenomenon; therefore its distribution in space is not random (National Institute of Justice (NIJ website). Crime analysis methods are important because they help to identify the different geographic patterns in criminal behavior. There are many conventional tools that allow crime data analysis, but GIS software can create a single visual output that combines multiple data layers into a meaningful output. The analysis between crime and other factors, for example, demography, housing, income, or social conditions, can lead to the understanding of the place and crime relationship based on the conditions compared.
GIS started in era of Mainframe computer, at that time it was a costly affair and not many law enforcing agencies can afford this technology, but the migration of GIS from mainframe to desktop computer has provided the law enforcing agencies a cost effective option for crime control. GIS has evolved as a powerful analytical tool in the last few decades. Due to the slashing down of prices of GIS software, this technology is now easily available to any law enforcing agency in the world.
Information management has always been a main concern for Law enforcement authorities, especially the location information. Traditional law enforcement approaches–confidential information through informers, street investigations, and undercover operations—are effective ways of data collection. However, data collection without data analysis is of no use, GIS allow effective integration and analysis of data to identify, apprehend, and prosecute suspects; it also helps the law enforcing agency to provide against crime through effective allocation of resources.
Today, with the rapid advancement of technology, a computer-based technique for exploring, visualizing, and examining the occurrences of criminal activity is essential. One of the more influential tools facilitating exploration of the spatial distribution of crime is GIS. The fundamental strength of GIS over traditional crime analytical tools and methods is the ability to visualize, analyze and explain the criminal activity in a spatial context. Certain environmental factors, such as the physical layout of the area, proximity to various services and land use are likely to influence criminal behavior and it is necessary to take them into account when analyzing the crime data.
The majority (91%) of law enforcement departments using GIS software reported the use of geo-coding. This method is the initial and vital step in the creation of a geographical data collection database, so that the data includes exact time and location information. Consequently, modern GIS software allows law enforcement agencies to produce more versatile electronic maps by combining their crime databases of reported crime locations with digitized maps of the target areas.
Crime is a complex, multi-dimensional event that occurs when the law, offender and target (refers to a person in personal crimes and an object in property crimes) converge in time and place (such as a street corner, address, building or street segment).
Fig: Spatial distribution of the density of motor vehicle theft for each day of the week in adelaide study area
Crime pattern theory:
As offenders move through routine activities of home, school, work, entertainment (shopping and recreation) they develop knowledge of the paths to their routine activities as well as areas around routine activities (personal awareness spaces). Different offenders may have different awareness spaces which may overlap. Generally, motivated offenders will discover potentially good target areas which offer a good choice of targets and low risk within their awareness space, although some will seek out uncharted areas Consequently areas within the general urban space that are part of most individuals selective target areas will have the most numerous crimes.
Hotspot identification using GIS
The non-random spatio-temporal distribution of crime suggests the existence of clusters or hotspots of crime in space and time Sherman et al. (1989; Sherman 1995) found that in Minneapolis of 323,000 service calls to police in 1986, found that a small number of hotspots produced most of the crime in the city (50% of the calls came from only 3% of the locations).
A crime hot spot is generally defined as an area containing dense clusters of criminal incidents. Identifications of hotspots helps public safety institutions allocate resources for crime prevention activities. This geographical analysis is usually made based on crime pin maps of reported crime events over a certain period, Before the recent technological advances, law enforcement agencies typically placed colored pushpins in wall maps to visualize individual crime events and examine the spatial distribution of crime locations.
This was a popular approach for detection of crime ‘hot spots’. Now this can effectively done using GIS, it permits the analyzers not only to draw the hot spots but also allow the analysis of hot spot over a period of time, the location of hot spot on week days for motar vehicle theft for may be different from that of week end. Geo-coding is necessary for generating the GIS based hotspot maps, it assigns an x and y coordinate to an event, or address, so it can be placed on the map. This allows fast and accurate visualization of data on the map.
Fig: The homicide occurrences on the map of Homicides in Washington, D.C. in years 1994-95 shows geo-referenced locations of crime data
The law enforcing agencies can control the crime using GIS in two different ways.
- Reducing Crime
- Investigating Crime
Fig: Effective Casual and Professional crime control with GIS
This is proactive method of crime control, this is a preventive measure which the law enforcing agencies undertake to prevent the crime form happening. The law enforcing agencies have limited resources, the number of patrol cars and the manpower available is fixed, in such a scenario the effective usage of resources is very important, GIS act as an effective tool to achieve this objective, the hot spots of crime are identified using GIS maps and then their location on maps are analysed in relation to different factor such as population density, average income etc. Location of hotspot in low income group area suggest that the offender may be committing the crime because of poverty, in such case providing employment to the people of effected area may lead to decrease in crime. If the hotspot is located near the abandoned buildings then increase of patrol near these buildings will decrease the crime in the area.
The hotspot identification using GIS; helps the law enforcing agencies to effectively use their resources.
The hotspot analysis also helps the law enforcing agencies to take preventive action in cases of serial crimes such as serial murder, since the behavior of offender is governed by the geographic environment around him, the offender is likely to choose its next target in a manner which has some co-relation with the previous ones this approach is known as pattern matching , this gives the law enforcing agencies some awareness about the offender next move and hence the law enforcing agencies have a chance to nab the serial crime offender and hence prevent the offender from committing the next crime.
This is a reactive approach, in this the law enforcing agencies came into action once the crime has been committed, investigating crime basically deals with the crime investigation and bringing the offender to justice. The investigating approach calls for lot of analysis, it looks into happening of similar previously and it also tries to figure out the suspects based on their previous criminal records. This approach calls for the homicide experts, detectives, under cover officers, finger print analysis along the pattern analysis of crime committed. The pattern analysis in crime investigation is a crucial part and it can be done effectively using GIS.
The crimes can broadly be divided in two main category
- Casual or Opportunistic crime
- Professional crime
Casual or opportunistic crime:
This type of crime behavior is primarily for personal reasons, the murder might take place due to a quarrel between two parties or a theft of vehicle might take place because the offender needed it for some personal reason. In these crimes the detectives and homicide expert find easy to investigate the crime, the offender of these crimes are basically committed by people who lost control on themselves for a movement, as these people are not professional criminals so they leave number of clues at crime site which make it easies for homicide experts and detectives to nab the offender. Causal or opportunistic approach can well do without GIS in most cases, as the one or two sporadic crime event in isolated locations hardly form a pattern.
This type of crime is behavior is normally by organised gangs, which commit crime knowing the consequences of the crime. Such crimes are committed by highly professional people and it is very difficult for the homicide expert and detective to generate a lead in these types of crime, the professional criminals hardly leave any clues which makes the job of detectives and homicide expert all the more difficult. The GIS can be a handy tool in these types of crime. In professional crimes offender are more likely to express preference for a particular time or place as their behavior is constant over a period of time, the indulgence in crime is not new to the offender, but it becomes phenomena for the offender, in such cases the offender is more likely to present a pattern in his crime related behavior. The GIS analysis can be very effective in this case; the pattern of crime can be generated over a period of space or time.
A study conducted by Leakha M. Henry1 and Brett A. Bryan in September 2000 tries to identify the pattern of Motor Vehicle Theft [MVT] in Australia . The pattern of MVT over the week was studied and from Monday through Wednesday, MVT was relatively moderate in suburban hotspots such as Modbury and Oaklands Park. On Thursday, MVT was primarily concentrated around suburban hotspots. The Modbury hotspot peaked at a high 80 incidences/km^2. The density was generally lower in Adelaide, Adelaide peaking at only 30 incidences/km^2 and North Adelaide up to 10 incidences/km^2. On Friday, there was a shift of MVT to Adelaide, with a peak of 60 incidences/km^2 in the Adelaide and 25 incidences/km2 in North Adelaide. Generally, the density for the Adelaide was high and spread outwards into Hindmarsh and Kensington & Norwood. The density in suburban hotspots, such as Modbury and Oaklands, was moderate at 30 cases. The MVT pattern on Saturday was similar to Friday. However, density in Adelaide increased to 80 incidences/km^2. The Glenelg also increased to 25 incidences/km^2. On Sunday, the density of MVT in Adelaide was still high at 60 incidences/km^2. Suburban hotspots displayed reduced activity of up to 10 incidences/km^2.In summary, the spatial distribution of MVT varied with the day of the week. The Adelaide hotspot was most intense from Friday through to Sunday. Throughout the rest of the week it remained moderate at about 30 incidences/km^2. The suburban hotspots were most intense on Thursdays with late night shopping, but moderate on other days and on Sundays were relatively low.
The need of effective utilization of GIS for Causal and Professional crime control has already been emphasized in the paper. Once a law enforcing agency decides to use GIS for crime control it has definite edge over offenders. The law enforcing agency can effectively use its resources by having a combined application program which combine the benefit of traditional analysis (such as finger print matching) with modern technology i.e., GIS and GPS. The Detective and Homicide experts can be armed with hand held GIS and finger print enabled devices, this will help them to apprehend the culprits in a better way. The GIS and GPS enabled Petrol cars can be a added benefit as this will help the law enforcing agency to reach the crime spot in no time. The GPS technology can effectively trace the location of a call for help to police using Location Based Services, once the location of crime is established the base station can then directed the patrol car nearest to the crime spot for attending the crime this can be easily done using GPS.
Resources needed to implement GIS system for crime control:
Data: The most important and often the most expensive part of an effective GIS program is data that is specially coded to include information about location. Location can be noted by the use of coordinates of latitude and longitude, elevation, zip codes, highway mile markers and so on.
Standards: Certain standards must be followed while accumulating the data so that it can be shared among different agencies.
Hardware & Software: GIS software package, computer and perhaps networking capabilities are needed. The technical sophistication of the software and the processing power of the hardware depends on the need of application.
Staff & Staff Training: An effective GIS program demands staff who are trained to understand the questions and problems that your organization faces, to know when spatial data analysis is appropriate, and to conduct analyses that meet the user needs.
Linkages: Spatial data is shareable and reusable. GIS applications developed in one place can often be used or modified for use elsewhere. So there is always a need to have linkages with other similar agencies who can share data among themselves.
Financial analysis for GIS investments
Determining the cost-benefit of an investment in GIS is an important and often difficult undertaking. One of the reasons for the difficulty is that GIS programs often allow law enforcing agencies to do things they have not been able to do before–therefore a true financial analysis before and after implementation is not possible. Nevertheless, the costs and benefits of a GIS program can be identified and estimated and this kind of assessment should help one to make sound investment decisions. Some of the costs to consider include: a feasibility study or needs assessment, hardware, software, maintenance contracts, data entry, data transfer, data purchases, data development, training and technical support for system users, supplies, overhead such as rent and utilities, and salaries. Benefits are much more difficult to quantify than costs and they depend on the applications the law enforcing agencies will run. Some common benefits are efficient utilization of resources; time saving in nabbing professional offenders and establishing the pattern in crimes.
It is recommended and highly suggested to use GIS to map, monitor and check, crimes in major cities. Also, the cost involved in procuring and installing such GIS data will be less when compared with the amount of distress people are put to after being attacked and killed by the criminals. The time has come when the law enforcing must implement the GIS so as to effectively use their resources and control crime. The developed countries have already implemented such system, now it’s the turn of developing countries to switch to GIS system. In India Police agencies of Bangalore, Hyderabad, Goa, Mumbai, Delhi and Kerala are using customized GIS software, the application of GIS in Indian policing is still in a rudimentary stage and there is tremendous scope of improvement.
- Leakha M. Henry1 and Brett A. Bryan, Visualising the spatio-temporal patterns of motor vehicle theft in Adelaide, South Australia, 2000.
- Mike Tulis, Use of GIS in Neighborhood Crime Mapping and Analysis, 2003
- David Ashby & Tessa Anderson, Exploring data issues in police performance, 2003