CHAPTER TWO: EVIDENCE THAT GIS WORKS IN LAW ENFORCEMENT
There are innumerable illustrations of how geographic information systems work successfully in law enforcement. A leading example is the New York City Police Department's CompStat crime mapping briefings, which made crime analyses available daily in place of a system where beat-level crime analysis often took up to six months (Gordon, 1997). But GIS has had dramatic results not just in large jurisdictions but across the range of law enforcement departments. Virtually all of the research team's interviews brought to light success stories which give evidence of this point. The policy implication of this research finding is that the issue for local, county, and state law enforcement officials is no longer whether crime mapping is an effective law enforcement tool, but rather how and when it is to be implemented.
Dimensions of Crime Mapping Effectiveness
Crime mapping is effective in gaining leadership support and collaboration
The Gallatin, TN, respondent discussed how crime mapping helped mobilize a community for law enforcement purposes:
"Last December we noticed a trend ... so we pulled out a map and essentially pinned [a set of crimes] to a map and found them to be pretty well clustered within a certain area of town called our Clearview community. And when we looked at that, we then went with the strategy of going door-to-door and actually canvassing the neighborhood, ...we took some pamphlets that we had published, how to secure your residence, how to start a neighborhood watch, and literally went to over 348 residences ... that we knocked on doors and talked to folks about things, and we got some actually really good leads on a couple of the burglaries ... And we actually even discovered a couple of burglaries that hadn't been reported previously ... When we did the survey in the Clearview community ... we brought a council member in, explained this was what we'd found, and he was just amazed, and probably because he hadn't even really considered it that bad, but were able to actually rally his support once we'd shown him what we had done, and that actually benefitted us even more."
Crime mapping is effective in identifying concentrations of crime
The Baltimore County, MD, interview revealed how crime mapping is effective in routine identification of crime patterns:
"We used a crime smoothing method on auto thefts to identify an area where we thought there was a greater likelihood that these offenses were going to occur, and I was just very recently notified that led to seventeen arrests for motor vehicle theft, which is just really outstanding, and since those arrests, the problem has really abated in that area."
Crime mapping is effective in predicting crime patterns
From the Vacaville, CA, interview: "We had a robbery string occurring and I did a projection when the next crime in that series would occur, providing a day, time and also a map ... and they caught the guy!" Likewise, from the Los Angeles County, CA, interview: (1)
"In 1998, we had a series of eight armed robberies up in our high desert area. The suspect became labeled the Bandanna Bandit ... [Crime Analyst Laura Bettencourt] used a geographic analysis to identify the likely future targets, and times and days of the next hits. Based on that information, a surveillance was set up on the primary targets and the bottom line was the suspect was observed entering that location and attempting to hold it up. The deputies intervened and a gun battle ensued and the suspect was killed."
Crime mapping is effective in reinforcing community policing
From the Redlands, CA, interview: (2)
"In our community policing initiatives we were able to show where crime was occurring to Neighborhood Watches and to our community policing officers. They are able to go out and share this information with the businesses in their areas and offer suggestions on additional lighting or ways to bring down the crime, and then show that decrease in crime once we've put into place some of the initiatives. The maps were very helpful there."
Likewise, the Lenexa, KS, interview noted,
"We put static crime maps out on our web site and that's a big hit with the public." (3)
Crime mapping is effective in planning meetings
From the Osceola Country, FL, interview:
"We've done pinpoint maps on a weekly basis, and broken it down by zones, and they are utilized in the upper level management meetings on a weekly basis, and the upper level management people are eating it up, you know, they look for it, and they're depending on it. We've had an excellent response. We are a visual people, you know. We relate visually; you can absorb a lot more information visually than you can through reading, so mapping, by nature, can carry a great deal of information in one look."
Crime mapping is effective in allocating resources
The Wilson, NC, Police Department routinely uses mapping in reallocating resources: (4)
"Based on maps of calls for service information, and incidence information, we realigned the four districts to make them even. And we found out, because of our mapping, and because of our crime analysis, that what we thought at one time was the high crime radial, another area was the high crime radial, so we had to increase the manpower in that district, as opposed to the district we thought we were going to have to increase, and it was all due to the crime analysis and to the mapping. Sometimes it's weekly that we reallocate manpower. Sometime we take from other districts, when we identify a fairly common problem, and try to stop it before it gets too bad, so we do it, we can do it in a week, take two units away from that one and say you need to go over there to this part, because the maps and the crime analysis is showing that we need to put out there."
Crime mapping is effective in increasing staff efficiency
Eric Kim wrote this about the Wisconsin Department of Corrections use of GIS in Community Corrections with probationers and parolees in Dane, Milwaukee, and Racine Counties:
"[The GIS system] has been pivotal in case assignments and reducing the amount of travel time for staff when conducting home visits. Some uses for the GIS in the Racine Area Project: immediate verification of addresses of offenders at the time of intake; analyze location of sex offenders in proximity to schools: define new neighborhoods based on offender concentration to assign and allocate staff based on offender profiles and to increase staff knowledge of the neighborhood they work in and therefore enhance public safety as well as the safety of the agents; and assigning new cases based on offender location." (Source: Crimemap list, email of 11 May 2000).
Crime mapping is an effective tool in patrol redistricting
From the Austin, TX, interview:
"Another success story would be patrol redistricting ... we tied response times and calls for service to geographic areas that went out to the different area commanders, to get their input on the districting needs - widely received - everyone really loved it because it's been the first time they've ever seen essentially a spreadsheet put in a graphical format so people could actually see where their high concentrations of calls were, where the high response times were."
Crime mapping is effective in search operations
From the Los Angeles County, CA, interview:
"[GIS was applied] in 1996, in a rather high profile homicide case. Linda Sobeck, former Raiderette, was killed by a photographer ... Part of the issue was that the suspect had confessed to accidentally causing Sobeck's death, and eventually led investigators to where he had buried her in the mountains, and some of the events leading up to that were found to be inadmissible in court. The defense argued that the body and, of course, all the evidence gathered from the body, should not be admissible either. Based on our recommendation, the prosecutor, the Deputy DA Stephen Kay, argued 'inevitable discovery,' that we would have found the body based on information in geographic analysis, identifying the highest probability areas that the body would have been buried, and based on that information, there was an 89 percent probability that the victim would have been found without the suspect's testimony."
Crime mapping is effective in communicating to juries
From the Redlands, CA, interview:
"One of our examples was a known cat burglar. We were able to map out his home address, as compared to where the patrol officers were, contacting him in the evenings through field interrogation cards, and then any other place that we stopped him where the burglaries were occurring. We had all those different layers that we could overlay on each other, and see exactly what the pattern was. So that was very helpful. And that also went to court with him, and showed the jury that that this is how it happened, and this is how we tracked him, so it was very helpful."
From the Cary, NC, interview:
"One example was, in 1995, they had a murder case where a man pushed his wife over the edge, and they took measurements and everything. They drew maps, aerial photograph maps, and actually took measurements from where the scream was heard to where she actually fell."
In this case also, mapping was an important part of the strategy of communicating evidence effectively to a jury.
Chapter summary
GIS as an information technology began in the natural resources area when computers were "mainframes". As information technology migrated from mainframe computers to desktop computers, GIS followed this migration. Desktop applications of GIS enable law enforcement officers to take pin maps off station house walls and deploy them to the hands of officers at the beat level. This migration has an empowering effect on law enforcement. GIS can be used effectively to map crime risk and resiliency factors for the community and is a pro-active tool for the prevention of crime. When asked, "Do you think that for the investment that you've made in crime mapping has paid off for you?" C. K. Lamm of the Wilson, NC, Police Department said:
"Oh yes, before GIS we had a burglary here, we had a burglary there, but with GIS, with the mapping, with the pinpointing, we really know what's going on, and that's really good. I think it's really paid off."
In fact, as Lamm's supervisor, Major Billy White noted, crime mapping was so cost-effective that the department reallocated resources to make it possible:
"We put in for a crime analyst in the budget, but they denied that position, but we felt that it was so important, that we get involved in mapping, that we took a man off the street to do it. And that man is doing more work and more for the department, off the street, than we could do with 10 or 12 of these officers. So go for it. Do what it takes to do it."
Crime mapping has payoffs not only in discerning crime patterns but also in more efficient resource allocation, more effective community policing, and better strategic planning and accountability.
Notes
1. And from the Austin, TX, interview:
"One success story would be a flasher case that we had going on where a crime analyst looked at crime, went out and did what we call environmental surveys, to look at geographic factors that were leading to crimes occurring, and plotting that out, looking at other factors, looking at a GIS analysis, and then coming up with businesses and travel patterns, entrance/escape routes, and then coordinating with undercover detectives to survey a particular area, and they ended up catching the guy. Definitely a big success story." Using a more sophisticated mapping system, the Baltimore County Police Department is able to integrate crime mapping with targeted community notification, resulting in more tips and arrests:
"I would have to say a success story is our ability to identify a crime series and anticipate successfully where we believe the offender might be hitting next. That's in terms of time and place, and we recently did that with a series of grocery store robberies, well, we called him the "Grocery Store Robber," but he actually was hitting different commercial locations. The interface with our auto-dialing system has proved to be very successful. The ability, once a crime pattern has been identified, to select out from the target community all households that have a registered or listed phone numbers, and then pre-recording a message which basically alerts the households that there's a crime problem, and then giving them ideas about what they could do to reduce their chances of being victimized. That has led to several arrests. I mean, it's certainly reduced crime ... And maps are used by commanders and their representatives, community outreach officers, etc., when they go out to community meetings, and discuss crime problems with the community. The maps are very helpful. " The Arizona Association of Crime Analysts has developed guidelines for posting crime maps to the Internet, and these guidelines have been recommended by staff of the Police Foundation:
1. No address-specific information on residences.
2. Addresses for residences should only be narrowed down to hundred-block ranges.
3. Address-specific information for businesses could be identified if a crime trend, pattern, etc. is identified.
4. Pin map property-related crimes (no individual addresses are identified).
5. Use only thematic maps for crimes against persons unless a trend or pattern is identified in which case pin mapping is reasonable as long as the addresses of residences are not identifiable.
6. Disclaimers should be placed on maps and statistics.
7. Map Web sites should contain links to community and crime prevention sites.
Contact Dr. Rachel Boba, Director of the Police Foundation's Crime Mapping Laboratory, or Mary Velasco, Research Associate, Crime Mapping Laboratory, Police Foundation, 1201 Connecticut Avenue, NW, Suite 200, Washington, DC 20036; mvelasco@policefoundation.org. See also Dr. Boba's article, "Using the Internet to Disseminate Crime Information," in the October, 1999 issue of the FBI's Law Enforcement Bulletin, available in PDF format at http://www.fbi.gov/library/leb/1999/leb99.htm. Reagan McClung of the Crime Victims' Institute of the Attorney General's Office in Austin, Texas, wrote:
"We have purchased a GIS system to map out the service providers in Texas, Crime
Rates, Victims, etc. The analysis that GIS has provided us has been crucial in allocating
grant money to law enforcement agencies, providing statewide education courses, and
automated victim notification to victims, etc." (Source: Crimemap list, email of 8 May
2000).