Jurisdiction – Villaveces et al. (2000)

Study Reference:

Villaveces, A., Cummings, P., Espetia, V. E., Koepsell, T., McKnight, B., & Kellermann, A. L. (2000). Effect of a ban on carrying firearms on homicide rates in 2 Columbian cities. Journal of the American Medical Association, 283(9): 1205-1209.

Location in the Matrix; Methodological Rigor; Outcome:

Jurisdiction; Focused; Proactive; Moderately Rigorous; Effective

What police practice or strategy was examined?

The study evaluated the effect of an intermittent police-enforced ban on carrying firearms on the incidence of homicide in urban Colombia by examining Cali, Colombia, during 1993 and 1994 and Bogotá, Colombia, from 1995 through August 1997. The ban was a part of a larger program for Development, Security, and Peace, known as DESEPAZ, in an effort to stem the city’s rising rate of homicide. The carrying of firearms was banned on weekends after paydays, on holidays, and on election days. During intervention days, police established checkpoints throughout the city and, at their discretion, searched individuals. Searches for weapons were also conducted during traffic stops and other law enforcement activities. Individuals in possession of a legally acquired firearm were fined and had the weapon temporarily confiscated. Those without proof of legally acquiring the firearm were to be arrested and the firearm permanently confiscated. Enforcement included establishment of police checkpoints and the searching of individuals during traffic stops and other routine law enforcement activity.

How was the intervention evaluated?

The study design used interrupted time-series with multiple replications. The public was notified of the ban through the media. In Cali, the intervention was applied on 34 occasions for a total of 89 days. In Bogota, the intervention was applied on 22 occasions for a total of 67 days.

What were the key findings?

The incidence of homicide was lower during periods when the firearm-carrying ban was in effect compared with other periods. An intermittent citywide ban on the carrying of firearms in 2 Colombian cities was associated with a reduction in homicide rates for both cities.

What were the implications for law enforcement?

The authors suggest that a program of this type may not have similar effect in cities where homicide is less common, and that constitutional restrictions on police search procedures would prevent transferring the methods used in Cali and Bogota to any city in the United States.

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