an analysis of omitted variable bias that uses juveniles, who are generally exempt from federal felon-in-possession charges, as an additional in-city control group. In his subsequent analysis of the Raphael-Ludwig data, Levitt (2003) suggests that the expectations of a large decrease in crime associated with Project Exile were probably unrealistic, given the small number of additional felon-in-possession convictions per year (roughly 80) and the small increase in total punishment in Richmond (240 extra person-years of imprisonment that would be associated with an estimated 2.5 percent reduction in crime in Richmond). Greenwood (2003) also speculates that Project Exile did not focus sufficiently on the most dangerous offenders associated with the bulk of firearm-related crime in Richmond.
Mandatory sentencing laws, which require a mandatory penalty for unlicensed or otherwise unlawful carrying of a firearm, seek to reduce gun use in unpremeditated crimes by deterring the casual carrying of firearms in public places. The best known example of laws that institute a mandatory penalty for unlawful carrying is the Massachusetts Bartley-Fox gun law.
The Massachusetts legislature enacted the Bartley-Fox gun law, which mandated a one-year minimum prison term for the unlicensed carrying of firearms and a two-year sentence for crimes committed while possessing a gun, to reduce the incidence of firearm-related crime as well as the illicit carrying of firearms (Beha, 1977). The amendment was adopted in July 1974 and became effective beginning in April 1975. Two months prior to the law’s effective date, a concerted campaign was launched to characterize the impending consequences in the following terms, “If you are caught with a gun, you will go to prison for a year and nobody can get you out” (Pierce and Bowers, 1981:122).
While the mandatory sentence provision removed most judicial discretion in sentencing a defendant convicted of illegally carrying a gun, the defendant could in fact escape the 1-year sentence in a variety of ways (Deutsch and Alt, 1977). If someone was apprehended with a firearm on his person, the police could file a charge of illegal possession, which does not carry a mandatory minimum, rather than a charge of illegal carrying. Later in the process, prosecutors could also press for the lesser possession charge regardless of the initial police charge. Judges and juries could also find the defendant guilty of a lesser charge. As Zimring commented, “the one-year minimum will only invoke mandatory one-year jail terms for carrying without a license to the extent that police, prosecutors, and judges want it to produce such results. If there is strong resistance from any single link in this chain, the mandatory minimum can be avoided” (as quoted in Deutsch and Alt, 1977:545).