David McDowall, Colin Loftin and Brian Wiersema, A Comparative Study of the Preventive
Effects of Mandatory Sentencing Laws for Gun Crimes, 83 J. Crim. L & Criminology 378
(1995)

“Our analysis is based on six city-specific case studies, which monitored the
effects of mandatory sentencing on violent crime in Detroit, Jacksonville,
Tampa, Miami, Philadelphia and Pittsburgh. The key features of the laws
were the same in each area. First, each law required judges to impose a
specified sentence on defendants convicted of an offense involving a gun.
Second, mitigating devices such as probation, suspended sentences and
parole were prohibited.” Id.at 378-379.

“Although the results of the case studies are complex, no individual study
provides clear support for the proposition that mandatory sentencing reduces
firearm violence.” Id.385.

Steven Raphael and Jens Ludwig, “Do Prison Sentence Enhancements Reduce Gun
Crime? The Case of Project Exile,” Evaluating Gun Policy, Jens Ludwig and Philip J. Cook,
eds. Brookings (2003).

Evaluating the impact of Project Exile and mandatory sentencing
enhancements on gun-related violence in Richmond, VA.

“[T]he reduction in Richmond’s gun homicide rates surrounding the
implementation of Project Exile was not unusual and that almost all of the
observed decrease probably would have occurred even in the absence of the
program.” Id.at 252.

“Our analysis confidently rules out the possibility that Project Exile achieved
the dramatic reductions in gun violence that have been claimed in the past.
. .” Id.at 277.