Lallen Johnson, PhD

Assistant Professor of Criminal Justice

Office: PSA 205
Phone: 215.895.0277


  • PhD, Criminal Justice, Temple University, 2012

Research and Teaching Interests

  • Drugs and violence
  • Race, crime, and justice
  • Ecology of crime
  • Geographic information systems


Lallen Johnson, PhD, considers himself an interdisciplinary scholar, with research interests at the intersection of urban studies, crime, and place. His most recent research examines neighborhood-level effects of gaming establishments on crime; and, how structural shifts affect municipality-level violent crime hotspots within the Philadelphia Metropolitan Area.

Lallen is a 2010 Graduate Research Fellow of the National Institute of Justice. His funded research has examined the travel patterns of illicit drug arrestees in the Philadelphia region to understand the relationship between drug crime and violence. In addition to studying illicit drug crime, he has collaborated with colleagues to assess the effectiveness of state legislation on the diversion and abuse of prescription drugs in the state of Florida.

Before arriving at Drexel, Lallen was a visiting assistant professor of Criminal Justice at the University of Central Florida. He has taught courses on drugs and crime, communities and crime, and race and justice.

Selected Publications

  • Johnson, L.T., Taylor, R.B., & Groff, E.R. (in press). Metropolitan local crime clusters: Structural concentration effects and the systemic model. Journal of Criminal Justice.
  • Johnson, L.T. (in press). Drug markets, travel distance and violence: Testing a typology. Crime and Delinquency.
  • Johnson, L.T., & Ratcliffe, J.H. (in press). A partial test of the impact of a casino on neighborhood crime. Security Journal.
  • Johnson, L.T. (2014). Policing urban drug markets. In M. Reisig & R. J. Kane (Eds.), The Oxford Handbook of Police and Policing (pp. 34-48). Oxford, UK: Oxford University Press.
  • Johnson, L.T., Taylor, R.B., & Ratcliffe, J.H. (2013). Need drugs, will travel?: The distances to crime of illegal drug buyers. Journal of Criminal Justice, 41(3), 178-187.
  • Groff. E., Johnson, L., Ratcliffe, J.H. & Wood, J. (2013). Exploring the relationship between foot and car patrol in violent crime areas. Policing: An International Journal of Police Strategies and Management, 36(1), 119-139.
  • Johnson, L., & Ratcliffe, J.H. (2013). When does a drug market become a drug market? Finding the boundaries of illicit event concentrations. In M. Leitner (Ed.), Crime Modeling and Mapping Using Geospatial Technologies. New York, NY: Springer (pp. 25-48). New York, NY: Springer.