Violence Reduction in Joliet, Illinois: An Evaluation of the Strategic Tactical Deployment Program

51 

 

Although the results indicate a reduction in shots fired during the intervention periods, 

these reductions were not statistically significant. Similarly, though greater reductions in shots 

fired were achieved in the STD sectors compared to the non-STD sectors, both areas had 

reductions in shots fired and there was 

no significant difference in the relative change between 

pre-intervention and post-intervention periods in shots fired between targeted and non-targeted 

sectors. 

Furthermore, there was no difference between the STD only and STD+ components for 

shots fired.   

The lack of a statistically significant difference in shots fired between targeted areas and 

non-STD sectors may be explained in a number of ways. First, the aim of intervention was to do 

something about violent crime wherever it presented itself in the city. Thus, although sectors 11, 

16 and 22 were the primary patrol areas, STD patrols did intervene in other sectors. Second, the 

probation and parole component was a citywide intervention and did not specifically target the 

primary STD sectors. Third, it is possible that although the primary target sectors were 11, 16 

and 22, the intervention could have spillover effects to adjacent neighborhoods.  

Correspondingly, the STD intervention had no effect on robberies. In fact, robberies 

increased significantly during the STD-only time period. Similarly, though not statistically 

significant, there was an increase in monthly robbery counts during the STD+ period. Also, 

there 

was no significant difference in the relative change between pre-intervention and post-

intervention periods in robberies between targeted and non-targeted sectors.   

Study Limitations

 

Although the results show a city-wide decline (though not significant) in shots fired during 

the STD intervention period, it is important to note that there are several potential limitations in 

the evaluation. First, alternative activities within the city—such as other police activities, major 

---

52 

 

social or political changes, or other community strategies—may also be responsible for the 

observed trends. Second, the observed decline in shots fired might be nothing more than simply 

part of the secular nationwide declining crime trend. Third, the STD intervention was based on 

the identification of crime hot spots, the deployment of STD personnel to hot spot areas and the 

use of aggressive preventative patrol activities. STD deployment occurred primarily during 

weekends between the hours of 9PM to 1AM. Analysis of counts of confirmed shooting during 

these days and times revealed no difference across intervention time periods. Specifically, in the 

pre-intervention period, 46.2% of shots fired occurred between 9PM and 1AM, Friday – Sunday. 

There was no significant reduction in the number of shots fired during the STD only intervention 

(45.7%) or the STD + probation/parole intervention (47.1%).  These results were replicated when 

comparing STD sectors with non-STD areas across the three time periods. The percent of 

shootings during the weekend between 9PM – 1AM during the pre-intervention period for STD 

areas was 43.5% and for non-STD sectors 46.0%.  During the STD only intervention time period 

the respective percentages were 43.3% and 45.0% and during the STD+ time period the 

respective percentages were 45/1% and 46.0%.  Consequently, it is not clear from the aggregate 

data how much influence STD patrols had on the overall decline in shootings. Fourth, and most 

important, the evaluation of STD lacked any real experimental design or variable(s) that captured 

its activities and systematically compared them to trends in similarly situated comparison 

neighborhoods or cities. Therefore, it is not possible to authoritatively attribute the declining 

trend in shots fired to the STD intervention. 

Clearly, there is a need for further systematic 

experimentation on the impact of STD and similar interventions on violent crime. 

 

 

---

53 

 

References 

Baker, T. & Wolfer, L. (2003). The crime triangle: Alcohol, drug use, and vandalism. Police 

 

Practice and Research, 4, 47–61.

 

Braga, A. Weisburd, D. Waring, E. Mazerolle, L., Spelman, W. and Gajewski, F. (1999). 

 

Problem-oriented policing in violent crime places: a randomized controlled experiment. 

 Criminology, 37:5, 41–80.

 

Braga, A. (2007). Effects of hot spots policing on crime. A Campbell Collaboration systematic 

 

review available at 

http://www.campbellcollaboration.org/reviews_crime_justice/index.php

. 

Braga, A. & Bond, B. (2008). Policing crime and disorder hot spots: A randomized controlled 

 

trial. Criminology, 46, 577–607.

 

Braga, A. Papachristos, A. & Hureau, D. (2010). The concentration and stability of gun 

violence at micro places in Boston, 1980-2008. Journal of Quantitative Criminology, 26, 

 33–53. 

Brinkman, L. Olaghere, A. and Schirmer, S. (2010). State Recidivism Studies. Washington 

 

D.C.: The Sentencing Project. 

Burrell, W. 1999. “Getting the Most Out of Probation/Parole-Police Partnerships.” Community 

 Corrections 

Report 7:1-12. 

Chaiken, J. Greenwood, P. and Petersilia, J. (1976). The Criminal Investigation Process: A 

 

Summary Report. Santa Monica CA: RAND Corporation.  

Clarke, R. and Weisburd, D. (1994). Diffusion of crime control benefits: Observations on the 

 

reverse of displacement. Crime Prevention Studies 2, 165-84. 

Claridge, J. and Fabian, T. (2005). History and development of evidence-based medicine. 

 

 

 World Journal of Surgery 29:5, 547-553.  

---