Two non-partisan, respected federal government agencies recently examined gun controls and found no statistically significant evidence to support their effectiveness. In 2004, the National Academy of Sciences reviewed 253 journal articles, 99 books, and 43 government publications evaluating 80 gun-control measures. The researchers could not identify a single gun-control regulation that reduced violent crime, suicide, or accidents. A year earlier, the Centers for Disease Control and Prevention reported on an independent evaluation of firearms and ammunition bans, restrictions on acquisition, waiting periods, registration, licensing, child access prevention laws, and zero tolerance laws. Conclusion: none of the laws had a meaningful impact on gun violence.