Gun Crime Prosecution Act of 1999

Gun Crime Prosecution Act of 1999 - Requires the United States Attorney for each judicial district to: (1) appoint one additional Assistant U.S. Attorney for that district to be responsible for prosecuting only offenses under Federal law involving firearms or ammunition; and (2) require such Attorney to give priority to crimes of violence committed by individuals who have previously been convicted of such a crime and to offenses by individuals who have previously been convicted of a crime punishable by imprisonment for more than one year. Authorizes appropriations.