Résumé
In collaboration with the Service de police de la Ville de Montréal (SPVM), this study aims to improve the knowledge about the structuring effect of firearms on criminal violence. This study first identifies factors associated with firearms use in violent crimes and second, estimates the risk of fatal and non-fatal injuries associated with gun use. Data used in the present study come from the Module d’information policière (MIP), for the period of 2011 to 2012. Data were analyzed using a two-step strategy. First, logistic regressions were conducted to pinpoint factors associated with firearm use in violent crime. Second, estimates of the average treatment effect were computed using the propensity score matching (PSM) technique. PSM is an innovative statistical strategy that attempts to reproduce conditions of controlled experiments when cases were not randomized in the first place. In general, results show that firearms are more frequently used in gang-related crimes where individuals attack relatively non-vulnerable targets (young males accompanied by other persons). Despite these characteristics, firearm use increases the risk of fatal injuries in violent altercations, but lessens the risk of non-fatal injuries, among other things, in the case of robberies. Findings establish that firearms facilitate the perpetration of violent crimes, even in the hands of the strongest offenders. Results also suggest that other weapons are poor substitutes for firearms. Although the findings cannot fully corroborate firearms as the great equalizer, these weapons do confer several advantages to their user(s). Firearms also appear to be a sufficient threat in the case of robberies, where additional injuries are not necessary to successfully commit the crime. .