The Brady Handgun Violence Prevention Act (Brady Act) requires criminal history background checks by the Federal Bureau of Investigation (FBI) and state agencies on persons who attempt to purchase a firearm from a licensed dealer. In 2009, the FBI and state agencies denied a firearm to nearly 133,000 persons due to National Instant Criminal Background Check System (NICS) records of felonies, domestic violence offenses, and other prohibiting factors. Enforcement of the Brady Act, 2009 reports on investigations and prosecutions of persons who were denied a firearm in 2009. The report describes how the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) screens denied-person cases and retrieves firearms that were obtained illegally. Statistics presented include charges most often filed against denied persons by United States Attorneys and results of prosecutions. Investigation statistics from two states are also presented. Key statistics are compared for the years 2009 and 2008. Statistical highlights are presented in the body of the report and complete details are included in an Appendix.