Oh, please point out exactly what flaws you found in the study. It is STILL a valid study, whether or not you like the source doesn't matter. But just to humor you, here's another.
http://www.cato.org/sites/cato.org/files/serials/files/cato-journal/2001/1/cj26n1-6.pdf
A number of studies from the 1970s and 1980s that do control for social and economic factors find no evidence of gun control reducing violent crime rates. Using regression analysis, state data, and a vector of social and economic variables, Murray (1975: 81) concludes that “gun control laws have no significant effect on rates of violence beyond what can be attributed to background social conditions.” In addition, he observes that“controlling for basic social factors, the data show that gun laws have no significant effect on access to firearms” and “differing rates of access to handguns had no significant effect on violent acts” (Murray 1975: 91). Lester and Murrell (1982: 131) did find that “states with stricter handgun laws in 1968 were shown to have lower suicide rates by firearms both in 1960 and 1970. These states also had higher suicide rates by ‘other means’.” According to the authors, their finding for 1960, well before the 1968 law, is troublesome because it castes doubt on any simple interpretation of the post-law 1970 results and suggests the desirability of constructing a more complete model that includes additional variables for explaining the variation in suicide rates across states. Finally, they observe, “No such effect of strict gun control laws was found for mortality from homicides by firearms” (Lester and Murrell 1982: 139).
Conclusion
Using state-level data and that for the District of Columbia, this study estimates both the impact of gun control on crime rates and the influence of crime rates on gun control. The measure of gun control adopted here is a comprehensive index, published by the Open Society Institute, covering 30 different facets of state gun laws, enforcement effort, and the stringency of local gun ordinances. The index weights upstream measures such as gun registration more heavily than downstream measures such as safe storage laws. It also weights regulations governing handguns more heavily than those on long guns. Using a vector of demographic, economic, and law enforcement control variables, the empirical analysis presented here provides no support for the contention that gun control reduces crime rates. In none of the regressions for the 10 categories of crime rates in 1999 and the 10 for 2001 is the measure of gun control statistically significant. The article tests another hypothesis, namely, that lax gun control laws in neighboring states undermine the effectiveness of state gun laws. It finds no support for this hypothesis. The proxy for neighboring state gun control is never significant in any of the 20 regressions estimated. By contrast, the article provides empirical support for the idea that high crime rates generate political support for the adoption on more stringent gun controls. Moreover, there is empirical evidence that the probability of adopting more gun regulations is positively related to the proportion of Democrats in the state legislature. The findings of this study that gun control is ineffective in reducing crime rates are consistent with the vast majority of other studies that use state data.