<P> Research by gun advocate John Lott found no impact of these bans on violent crime rates, but provided evidence that the bans may have reduced the number of gun shows by over 20 percent . Koper, Woods, and Roth studies focus on gun murders, while Lott's look at murder, rape, robbery, and aggravated assaults . Unlike their work, Lott's research accounted for state assault weapon bans and 12 other different types of gun control laws . </P> <P> In a 2013 report Samantha Bricknell from the Australian Institute of Criminology, Frederic Lemieux and Tim Prenzler compared mass shootings between America and Australia and found the "1996 NFA coincided within the cessation of mass shooting events" in Australia, and that there were reductions in America that were evident during the 1994--2004 US Federal Assault Weapon Ban . </P> <P> The assault weapons ban expired on September 13, 2004 . Legislation to renew or replace the ban was proposed numerous times unsuccessfully . </P> <P> Between May 2003 and June 2008, U.S. Senator Dianne Feinstein, D - CA, and Representatives Michael Castle, R - DE, Alcee Hastings, D - FL, and Mark Kirk, R - IL, introduced bills to reauthorize the ban . During the same time, Senator Frank Lautenberg, D - NJ, and Representative Carolyn McCarthy, D - NY, introduced similar bills to create a new ban with a revised definition for assault weapons . None of the bills left committee . </P>

When was the last time assault weapons were banned