Final Report Supported under award #95-IJ-CX-0111 from the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. Points of view in this document are those of the author(s) and do not necessarily represent the official position of the U.S. Department of Justice.
The views expressed are those of the author and do not necessarily reflect those of the Urban Institute, its board, its sponsors, or other authors in the series.
Note: This report is available in its entirety in the Portable Document Format (PDF).
Title XI of the Violent Crime Control and Law Enforcement Act of 1994 (the Crime Control Act) took effect on September 13, 1994. Subtitle A banned the manufacture, transfer, and possession of designated semiautomatic assault weapons. It also banned "large-capacity" magazines, which were defined as ammunition feeding devices designed to hold more than 10 rounds. Finally, it required a study of the effects of these bans, with particular emphasis on violent and drug trafficking crime, to be conducted within 30 months following the effective date of the bans. To satisfy the study requirement, the National Institute of Justice (NIJ) awarded a grant to The Urban Institute for an impact evaluation of Subtitle A. This report contains the study findings.
In defining assault weapons, Subtitle A banned 8 named categories of rifles and handguns. It also banned exact copies of the named guns, revolving cylinder shotguns, and guns with detachable magazines that were manufactured with certain features such as flash suppressors and folding rifle stocks. The ban specifically exempted grandfathered assault weapons and magazines that had been manufactured before the ban took effect. Implicitly, the ban exempts all other guns; several of these, which we treated as legal substitutes, closely resemble the banned guns but are not classified as exact copies.
Among other characteristics, ban proponents cited the capacity of these weapons, most of which had been originally designed for military use, to fire many bullets rapidly. While this capacity had been demonstrated in several highly publicized mass murders in the decade before 1994, ban supporters argued that it was largely irrelevant for hunting, competitive shooting, and self-defense. Therefore, it was argued, the ban could prevent violent crimes with only a small burden on law-abiding gun owners. Some of our own analyses added evidence that assault weapons are disproportionately involved in murders with multiple victims, multiple wounds per victim, and police officers as victims.
To reduce levels of these crimes, the law must increase the scarcity of the banned weapons. Scarcity would be reflected in higher prices not only in the primary markets where licensed dealers create records of sales to legally eligible purchasers, but also in secondary markets that lack such records. Although most secondary-market transfers are legal, minors, convicted felons, and other ineligible purchasers may purchase guns in them (usually at highly inflated prices) without creating records. In theory, higher prices in secondary markets would discourage criminal use of assault weapons, thereby reducing levels of the violent crimes in which assault weapons are disproportionately used.
For these reasons, our analysis considered potential ban effects on gun markets, on assault weapon use in crime, and on lethal consequences of assault weapon use. However, the statutory schedule for this study constrained our findings to short-run effects, which are not necessarily a reliable guide to long-term effects. The timing also limited the power of our statistical analyses to detect worthwhile ban effects that may have occurred. Most fundamentally, because the banned guns and magazines were never used in more than a fraction of all gun murders, even the maximum theoretically achievable preventive effect of the ban on gun murders is almost certainly too small to detect statistically with only one year of post-ban crime data.
With these cautions in mind, our analysis suggests that the primary-market prices of the banned guns and magazines rose by upwards of 50 percent during 1993 and 1994, while the ban was being debated, as gun distributors, dealers, and collectors speculated that the banned weapons would become expensive collectors' items. However, production of the banned guns also surged, so that more than an extra year's normal supply of assault weapons and legal substitutes was manufactured during 1994. After the ban took effect, primary-market prices of the banned guns and most large-capacity magazines fell to nearly pre-ban levels and remained there at least through mid-1996, reflecting both the oversupply of grandfathered guns and the variety of legal substitutes that emerged around the time of the ban.
Even though the expected quick profits failed to materialize, we found no strong evidence to date that licensed dealers have increased "off the books" sales of assault weapons in secondary markets and concealed them with false stolen gun reports. Stolen gun reports for assault weapons did increase slightly after the ban took effect, but by less than reported thefts of unbanned large-capacity semiautomatic handguns, which began rising well before the ban.
The lack of an increase in stolen gun reports suggests that so far, the large stock of grandfathered assault weapons has remained largely in dealers' and collectors' inventories instead of leaking into the secondary markets through which criminals tend to obtain guns. In turn, this speculative stockpiling of assault weapons by law-abiding dealers and owners apparently reduced the flow of assault weapons to criminals, at least temporarily. Between 1994 and 1995, the criminal use of assault weapons, as measured by law enforcement agency requests for BATF traces of guns associated with crimes, fell by 20 percent, compared to an 11 percent decrease for all guns. BATF trace requests are an imperfect measure because they reflect only a small percentage of guns used in crime. However, we found similar trends in data on all guns recovered in crime in two cities. We also found similar decreases in trace requests concerning guns associated with violent and drug crimes.
At best, the assault weapons ban can have only a limited effect on total gun murders, because the banned weapons and magazines were never involved in more than a modest fraction of all gun murders. Our best estimate is that the ban contributed to a 6.7 percent decrease in total gun murders between 1994 and 1995, beyond what would have been expected in view of ongoing crime, demographic, and economic trends. However, with only one year of post-ban data, we cannot rule out the possibility that this decrease reflects chance year-to-year variation rather than a true effect of the ban. Nor can we rule out effects of other features of the 1994 Crime Act or a host of state and local initiatives that took place simultaneously. Further, any short-run preventive effect observable at this time may ebb in the near future as the stock of grandfathered assault weapons and legal substitute guns leaks to secondary markets, then increase as the stock of large-capacity magazines gradually dwindles.
We were unable to detect any reduction to date in two types of gun murders that are thought to be closely associated with assault weapons, those with multiple victims in a single incident and those producing multiple bullet wounds per victim. We did find a reduction in killings of police officers since mid-1995. However, the available data are partial and preliminary, and the trends may have been influenced by law enforcement agency policies regarding bullet-proof vests.
The following pages explain these findings in more detail, and recommend future research to update and refine our results at this early post-ban stage.
Note: This report is available in its entirety in the Portable Document Format (PDF).
Researchers traditionally acknowledge assistance from others in completing a study. However, we received far more than traditional amounts of help. A host of people who cared about the questions we were asking generously donated their expertise, data, and time.
Our greatest debts are owed to our advisors, Bill Bridgewater and Judy Bonderman. Bill, as executive director of the National Alliance of Stocking Gun Dealers, and his wife Carole, editor of the Alliance Voice, shared with us a vast knowledge of guns and gun markets. As adjunct law professor at Catholic University and an occasional legal advisor to Handgun Control, Inc., Judy taught us much about the relevant laws. Both helped us frame the questions we asked. While Bill and Judy made successful careers as advocates of quite different perspectives on gun policy, they both respected the integrity of our work as disinterested researchers. Sadly, Bill passed away before our work was completed. We hope he would agree that we learned what he tried to teach us.
We also received substantial help from staff at the Bureau of Alcohol, Tobacco and Firearms. Ed Owen continued our education about firearms in the late stages of the project. He, Joe Vince, and Jerry Nunziato provided technical information and critically reviewed an early draft of this report. Willie Brownlee, Gerry Crispino, Jeff Heckel, David Krieghbaum, Tristan Moreland, Valerie Parks, and Lia Vannett all shared data and insights.
We are grateful to the following researchers and organizations who generously shared their data with us: Tom Marvell, of Justec Research; Scott Decker, Richard Rosenthal, and Richard Rabe of Washington University; David Kennedy and Anthony Braga of Harvard University; Glenn Pierce of Northeastern University; Stephen Hargarten, M.D., and Mallory O'Brien of the Medical College of Wisconsin; Weldon Kennedy, Loretta Behm, and Monte McKee of the Federal Bureau of Investigation; Denise Griffin of the National Conference of State Legislatures; Kristen Rand of the Violence Policy Center; Donald T. Reay, M.D., Chief Medical Examiner, King County, Washington; Michael Buerger of the Jersey City Police Department; Beth Hume and Maxine Shuster of the Massachusetts Department of Public Health; Yvonne Williams, Office of the Medical Examiner, County of San Diego; and Rebecca Knox of Handgun Control, Inc.
We appreciate the fine work of our Urban Institute colleagues who contributed to this report: Bill Adams, John Marcotte, John McGready, Maria Valera, and Doug Wissoker. We also appreciate research assistance by Sonja Johnson, Andrew Scott, Jason Greenberg, Kristen Mantei, Robert Moore, Rick Poulson, Veronica Puryear, and Claudia Vitale. We are grateful for O. Jay Arwood's expert work in producing this complex document. Finally, we appreciate the advice and encouragement of Lois Felson Mock, our National Institute of Justice grant monitor, and the thorough and helpful comments by anonymous reviewers inside and outside NIJ.
Any remaining errors or omissions are the responsibility of the authors.