Ferguson, Andrew Guthrie, Crime Mapping and the Fourth Amendment: Redrawing ‘High Crime Areas’ (March 2, 2011). Hastings Law Journal, Vol. 63, No. 1, 2011. Available at SSRN: http://ssrn.com/abstract=1774876
This article addresses how “crime mapping” technology has the potential to reshape Fourth Amendment protections in designated “high crime areas.” In the past few years, the ability of police administrators to identify and officially label “high crime areas” has rapidly expanded. Geographic Information Systems (GIS) and crime mapping technology has simplified the collection and analysis of crime statistics. These GIS crime mapping technologies can produce almost perfect information about the level, rate, and geographic location of crimes in any given area.
While effective policing tools, these technologies have constitutional consequences that are only now being considered. Under existing Supreme Court precedent, Illinois v. Wardlow, the fact that an area is designated a “high crime area” has Fourth Amendment implications. Such a finding in a suppression hearing can affect a court’s determination about whether law enforcement officers had “reasonable suspicion” to stop an individual suspected of a crime. As a result, in thousands of cases post-Wardlow, the designation of an area as a high crime area had a constitutional effect on the liberty interests of individuals living in those areas as well as a practical effect on courts analyzing the reasonableness of a Fourth Amendment stop.
Two questions frame this article. First, how does GIS crime mapping technology alter Fourth Amendment reasonable suspicion analysis? Or more pointedly, will this technology result in an implicit “high crime area exception” to the Fourth Amendment? Second, how does this technology alter police-citizen encounters in officially designated “high crime” areas? These foundational questions lead to a reevaluation and rethinking of the concept of high crime areas as understood by the courts. In answer to these questions, this article proposes a redefinition of the term that is consistent with existing crime mapping technologies.
Part one of this article sets out the history and development of GIS crime mapping technologies. Part two provides a brief overview of the technical requirements of GIS and explains how the technology works in practice, using three real world examples. Part three examines how courts have used (or not used) existing crime mapping technologies to address the Fourth Amendment “high crime area” question. Part four looks at the intersection of crime mapping technologies and the Fourth Amendment, exploring how these technologies shape our understanding of reasonable suspicion and restructure police-citizen encounters in these official “high crime areas.” Part five proposes a new framework for addressing the “high crime area” question, that suggests replacing the existing terminology with a more particularized and specific understanding of crime patterns in an area driven by GIS crime mapping technologies. The result will be a particularized assessment of specific crime patterns that will replace the “high crime area” terminology. Part six addresses some of the concerns with the use of any crime mapping technologies in terms of transparency, accuracy, fairness, equality, and ultimately the legitimacy of GIS crime mapping techniques. The article concludes with a proposed solution that rejects the “high crime area” terminology and replaces it with a more particularized and targeted framework for Fourth Amendment analysis.