"The number of suspects arrested for a federal offense declined slightly to 179,489 in fiscal year 2010 after reaching a record 181,726 suspects in 2009. The number of suspects arrested by federal law enforcement more than doubled, from 80,450 in 1994 to 179,489 in 2010 […]. In recent years, federal law enforcement activity has outpaced the later stages of cases processing in U.S. district court (persons charged, convicted, and sentenced to prison). From 2006 to 2010, arrests increased at an annual average rate of 6%, and matters opened by U.S. attorneys (i.e., investigations) increased at an annual average rate of 9%. In comparison, the number of suspects charged in U.S. district court increased at an average annual rate of 3% over this period, while both the number of defendants convicted in U.S. district court (up 3%) and the number of offenders sentenced to prison (up 2%) increased."
NCJ 239913; National Criminal Justice 239913
U.S. Bureau of Justice Statistics: http://www.bjs.gov/