Groups – Levchak (2021)

Study Reference:

Levchak, P. J. (2021). Pulling levers in New Haven, CT: An analysis of the TimeZup initiative and its impact on murder, robbery, and assault. Policing: An International Journal, 44(5), 875-892.


Location in the Matrix; Methodological Rigor; Outcome:

Groups; Focused; Highly proactive; Moderately Rigorous; No evidence of effect


What police practice or strategy was examined?

The study assessed the effectiveness of TimeZup, a pulling levers focused deterrence strategy implemented in New Haven, Connecticut, starting in August 1999, to reduce gun violence in the city. This strategy involved collaboration among local, state, and federal agencies to address gun violence through reactive and proactive law enforcement measures. Monthly 'lever pulling' call-in meetings were also held to deter potential offenders. Initially, reactive law enforcement actions included reviewing gun cases for federal prosecution. Proactive law enforcement was facilitated by coordinating patrol officers, detectives, and members of the U.S Attorney’s Office and the State Attorney’s Office to identify and monitor individuals involved in gun violence, checking for any criminal activities or probation violations. Lastly, at the monthly lever pulling meetings, at-risk individuals were invited to learn about TimeZup. They were cautioned about the collaborative efforts of local, state, and federal agencies to seek federal prosecution for gun offenses, while also being informed about available social services.


How was the intervention evaluated?

The authors examined crime data, including rates of murder, firearm robbery, and firearm assaults from periods before and after the focused deterrence intervention to assess whether there were any significant changes in crime trends following the intervention. This study used a quasi-experimental design, comparing crime rates in New Haven before and after the implementation of TimeZup (from January 1994 through November 2003) with those of six similar Northeastern cities over the same period.


What were the key findings?

Overall, the results suggested that TimeZup did not significantly affect murder, firearm robbery, or firearm assault rates in New Haven. A notable reduction in firearm robbery rates was observed in July 1997, which was prior to the official launch of TimeZup, and likely resulted from other lever pulling strategies already implemented by the New Haven Police Department. The data indicate that, despite the declining crime rates in New Haven throughout the 1990s, there is no evidence to attribute these decreases to the TimeZup.


What were the implications for law enforcement?

While pulling levers strategies have largely been effective, their impact can vary significantly depending on local conditions and the timing of their implementation. In New Haven's case, significant reductions in violent crime had already been achieved before TimeZup's introduction, making it more difficult to detect further effects from the new program. It is also possible that the program’s implementation and targeting were not sufficient to maximize effectiveness.


Where can I find more information about this intervention, similar types of intervention, or related studies?