The Justice Department's Bureau of Justice Statistics has developed a web-based tool to generate statistics on "suspects and defendants processed through the federal criminal justice system."
Federal Criminal Case Processing Statistics tool contains data from 1998 to 2010. Tables and trends are available for incarceration, law enforcement, and prosecution/courts.
Perhaps the most interesting feature of this service is the U.S. Code option, which allows a user to select one or more provisions of Title 18 and other criminal statutes to find statistics on the number of defendants in cases filed and cases closed; outcomes for defendants in closed cases; sentences given to convicted defendants; and mean prison or probation sentence or fine. Users can select multiple years and multiple offenses.
This tool is just on of the many sources provided by the BJS, a one-stop shop for federal criminal justice statistics.