Read "Firearms and Violence: A Critical Review" at NAP.edu. 2004. doi:10.17226/10881. ((The National Academies Press (NAP) publishes authoritative reports issued by The National Academies of Science, Engineering, and Medicine (NASEM)).
In relation to a 2001 study the National Research Council in 2005, stated "evaluation of the short-term effects of the 1994 federal assault weapons ban did not reveal any clear impacts on gun violence outcomes."
In 2004, a research report commissioned by the National Institute of Justice found that if the ban was renewed, the effects on gun violence would likely be small and perhaps too small for reliable measurement, because rifles in general, including rifles referred to as "assault rifles" or "assault weapons," are rarely used in gun crimes.((The National Institute of Justice (NIJ) is the research, development and evaluation agency of the United States Department of Justice))
The following comments were taken from a Factcheck.org article by Robert Farley titled, “Did the 1994 Assault Weapons Ban Work?” published on February 1, 2013.
The article quotes extensively from the 2004 study by Koper, Christopher S.; Woods, Daniel J.; Roth, Jeffrey A. (June 2004). "An Updated Assessment of the Federal Assault Weapons Ban: Impacts on Gun Markets and Gun Violence, 1994–2003 – Report to the National Institute of Justice, United States Department of Justice" (PDF). Philadelphia: Jerry Lee Center for Criminology, University of Pennsylvania. The 2004 study was mandated by the 1994 Act.
The report found that the share of gun crimes involving assault weapons had declined by 17 to 72 percent in the studied localities (Boston (72%), Miami (32%), St. Louis (32%), Baltimore (34%), Milwaukee (17%) and Anchorage (40%)―Koper 2004
The authors reported that "there has been no discernible reduction in the lethality and injuriousness of gun violence, based on indicators like the percentage of gun crimes resulting in death or the share of gunfire incidents resulting in injury."―Koper 2004
The report also concluded that it was "premature to make definitive assessments of the ban's impact on gun crime," since millions of assault weapons and large-capacity magazines manufactured prior to the ban had been exempted and would thus be in circulation for years following the ban's implementation.
“Although the ban has been successful in reducing crimes with AWs [Assault Weapons], any benefits from this reduction are likely to have been outweighed by steady or rising use of non-banned semiautomatics with LCMs [large-capacity magazines], which are used in crime much more frequently than AWs. Therefore, we cannot clearly credit the ban with any of the nation's recent drop in gun violence," the study concluded. "And, indeed, there has been no discernible reduction in the lethality and injuriousness of gun violence….”―Koper 2004
“What we found in these studies was that the ban had mixed effects in reducing crimes with the banned weaponry due to various exemptions that were written into the law. And as a result, the ban did not appear to effect gun violence during the time it was in effect. But there is some evidence to suggest that it may have modestly reduced shootings had it been in effect for a longer period.”―Koper 2004
“The final report concluded the ban’s success in reducing crimes committed with banned guns was “mixed.” Gun crimes involving assault weapons declined. However, that decline was “offset throughout at least the late 1990s by steady or rising use of other guns equipped with LCMs.”―Factcheck.org 2013
“Ultimately, the 2004 research concluded that it was “premature to make definitive assessments of the ban’s impact on gun crime,” largely because the law’s grandfathering of millions of pre-ban assault weapons and large-capacity magazines “ensured that the effects of the law would occur only gradually” and were “still unfolding” when the ban expired in 2004.”―Factcheck.org 2013
https://www.tandfonline.com/doi/abs/10.1080/13504851.2013.854294 “An examination of the effects of concealed weapons laws and assault weapons bans on state-level murder rates,” by Mark Gius, Pages 265-267 | Published online: 26 Nov 2013
“…the present study suggests that states with restrictions on the carrying of concealed weapons had higher gun-related murder rates than other states. It was also found that assault weapons bans did not significantly affect murder rates at the state level. These results suggest that restrictive concealed weapons laws may cause an increase in gun-related murders at the state level. The results of this study are consistent with some prior research in this area, most notably Lott and Mustard (1997). Applied Economics Letters. 21 (4): 265 267.doi10.1080/13504851.2013.854294.
Koper, Christopher S. (2013). Reducing Gun Violence in America: Informing Policy with Evidence and Analysis (PDF). Johns Hopkins University Pres
Christopher S. Koper, a criminology scholar, reviewed the literature on the ban's effects and concluded that its effects on crimes committed with assault weapons were mixed due to its various loopholes. He stated that the ban did not seem to affect gun crime rates, and suggested that it might have been able to reduce shootings if it had been renewed in 2004.