Calibrating Police Activity Across Hot Spot and Non-Hot Spot Areas

• Author: Cynthia Lum,Xiaoyun Wu,Christopher S. Koper
• Published date: 01 September 2021
• Date: 01 September 2021
• DOI: http://doi.org/10.1177/1098611121995809
• Subject Matter: Articles

Article

Calibrating Police

Activity Across Hot

Spot and Non-Hot

Spot Areas

Christopher S. Koper

1

,

Xiaoyun Wu

1

, and Cynthia Lum

1

Abstract

Maximizing crime prevention through large-scale implementation of hot spot policing

requires a more refined understanding of how to calibrate police activity across high

and low-risk areas. This study investigates these issues based on the experience of a

large urban police agency that substantially reduced proactive activities across a large

area due to resource cutbacks while also shifting a larger share of its declining

proactive work into prioritized micro hot spots. Time series models were used to

estimate the effects of these changes on crime-related calls in hot spots and non-hot

spot areas. Hot spots required higher levels of proactivity (expressed as rates per

day or per crime) to control crime, and serious crime rose in these locations

following modest reductions in proactivity. In areas outside hot spots, minor and

property crimes rose, but only after reductions of one-half to two-thirds in proactive

work. Violence was unaffected in these areas, and they did not experience acceler-

ated growth in crime relative to prioritized hot spots. These results help to illumi-

nate minimum levels of police activity that may be necessary to control crime in

places of varying risk. They also suggest that police can reduce proactive work by

substantial amounts in lower risk areas to place more emphasis on hot spots. Better

understanding of these issues is central to widespread, systematic operationalization

of hot spot policing as a means to reduce crime across large areas.

1

Department of Criminology, Law and Society, George Mason University, Fairfax, VA, United States

Corresponding Author:

Christopher S. Koper, Department of Criminology, Law and Society, George Mason University,

4400 University Drive, MS 6D12, Fairfax, VA 22030, United States.

Email: ckoper2@gmu.edu

Police Quarterly

2021, Vol. 24(3) 382–406

!The Author(s) 2021

Article reuse guidelines:

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DOI: 10.1177/1098611121995809

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Keywords

proactive policing, hot spots, urban crime, time series

“Hot spot” policing—i.e., policing focused on small geographic places or areas

where crime is concentrated—has been one of the most important policing

innovations of recent decades (Weisburd & Braga, 2019). The use of crime

mapping to identify hot spots is common among police agencies (Burch, 2012;

Reaves, 2010; Weisburd & Lum, 2005), and police cite hot spot enforcement as a

leading approach to the reduction of violence and other crime problems (Police

Executive Research Forum, 2007, 2008; also see Koper, 2014). Numerous eval-

uation studies also show that police interventions of various sorts focused on

hot spots reduce crime at these locations (for reviews, see Braga et al., 2019;

Lum & Koper, 2017; National Academies of Sciences, Engineering, and

Medicine (NAS), 2018; National Research Council (NRC), 2004; Telep &

Weisburd, 2012).

However, adapting hot spot policing from small-scale tests to system-wide

implementation across large areas or an entire jurisdiction (i.e., “scaling up” this

practice as described by Sherman et al., 2014) requires further understanding of

how to optimize police activity across different areas based on their risk levels.

In particular, practitioners need clearer guidance on the varying levels of police

dosage that may be necessary to manage both hot spots and lower risk areas

across a jurisdiction. Having more direct evidence on this issue would inform

assessments of how much policing is needed in hot spots and the degree to which

policing can be diverted from low risk areas to accommodate needs in hot spots

without facilitating crime displacement to low risk areas or otherwise under-

mining deterrence and prevention in those areas. Without such understanding, it

is not clear whether implementing a more widespread, systematic, and sustained

preventive emphasis on hot spots in everyday police operations can produce

large-scale aggregate reductions in crime (Nagin & Sampson, 2019; Sherman

et al., 2014; Weisburd et al., 2017; Weisburd & Telep, 2014). This study

addresses selected aspects of this problem using data from a U.S. city that

experienced substantial reductions in proactive policing activity across a large

area. Although not a formal test of a scaled-up hot spot policing effort, the

study examines key dosage issues raised above that are implicit in the scaling up

idea. Specifically, we investigate differences in the minimum levels of proactive

policing that are necessary to prevent crime in hot spots and lower risk loca-

tions. In addition, we examine the utility of shifting a larger share of proactive

policing into hot spots under these conditions from a macro, system-wide per-

spective. We then consider the implications of the findings for efforts to design,

implement, and evaluate hot spot policing operations on a larger scale.

Koper et al. 383