The Impacts of Large-Scale License Plate Reader Deployment on Criminal Investigations

Abstract

The use of automated license plate readers (LPRs) has spread rapidly among American police in recent decades. However, research on LPRs has been very limited and focused primarily on small-scale use of LPRs in patrol. This study expands the evidence base on LPRs by evaluating investigative use of a large-scale fixed LPR network in one populous city. Survival analysis methods were used to assess changes in the likelihood and timing of investigative case closures in this city following installation of a fixed network of nearly 100 LPRs. The analysis focused on auto theft, theft of vehicle parts, and robbery investigations, which account for most uses of LPRs by investigators. Case clearances for auto theft and robbery improved after the installation of the LPR network, particularly in places where LPRs were concentrated. However, these changes were not statistically significant in multivariate analyses, and patterns in the data suggest that other factors may have also contributed to higher clearances during the intervention period, particularly for auto theft cases. Results suggest that large-scale LPR deployment may have the potential to improve investigative outcomes for some serious crimes-particularly with more consistent use and better placement for investigations-but further assessment is needed. More generally, additional research is needed to determine the best uses of LPRs, the

Clearing homicides

“…As mentioned, however, this dichotomous variable may not capture the quality of that additional evidence or the extent or types of technologies that were used. Tests of specific technologies would be needed to understand better their impact of investigations (see, for example, Koper & Lum, ). If a specialized unit assisted with the investigation, the odds of solving the case increased by 159%, possibly suggesting that added resources to an investigation can be helpful in resolving homicide cases.…”

“…Doing so could provide more details about the sequential aspects of specific parts of the investigation, as well as greater ranges of values for each of our covariates. For example, as Koper and Lum () have discovered, the use of license plate readers are sometimes deployed at later stages of investigations when all other possible leads and efforts have already been tried. Thus, the use of that technology may be an indication of the difficulty of case resolution, not necessarily of investigative effort.…”

Examining Police Officers’ Perceptions of Automated License Plate Readers Before Technology Expansion

“…The potential benefits of ALPRs may extend beyond surveillance and deterrence-based activities in real-time or near real-time. Select agencies are beginning to recognize the impact of the technology on investigative efforts (e.g., identifying suspect movements, corroborating alibis; see Willis et al, 2018) and, subsequently, solve/clearance rates more specifically (Koper & Lum, 2019). For instance, in the aforementioned nationally representative survey of large agencies, only 10% to 12% of those with ALPRs reported using the technology “always or almost always” for investigating crimes against persons and property (Lum et al, 2019).…”

Effective police investigative practices: an evidence-assessment of the research

“…New video technologies such as body-worn cameras may also increase the detection of suspects and clearance of cases (see Ellis et al, 2015;Lum et al, 2019;Morrow et al, 2016). Koper and Lum (2019) find that license plate readers have modest positive impacts on case clearances for auto-theft and robbery but that large numbers of license plate readers are required to create those modest impacts. They also argue that license plate readers may have to be combined with other technologies (like CCTV) and policies that prompt more systematic use by detectives and officers to create these effects (also see Taylor et al, 2012).…”