"According to a 2008 survey of states, there were 92.3 million people with criminal records on file with states, including those individuals fingerprinted for serious misdemeanors and felony arrests. U.S. Bureau of Justice Statistics, Survey of State Criminal History Information Systems, 2008 (Oct. 2009), at Table 1. In some states, misdemeanor arrests for less serious crimes do not require fingerprinting, thus this figure is likely an undercount of people with criminal records. To account for individuals who may have records in multiple states and other factors, and to arrive at a conservative national estimate, the 92.3 million figure was reduced by 30 percent (64.6 million). Thus, as a percentage of the U.S. population over the age of 18 (232,458,335 in 2009 according to the U.S. Census Bureau, Population Division, available at http://www.census.gov/popest/), an estimated 27.8 percent of the U.S. adult population has a criminal record on file with states. This estimate is consistent with a Department of Justice finding that about '30 percent of the Nation’s adult population' has a state rap sheet. U.S. Dept. of Justice Office of the Attorney General, The Attorney General’s Report on Criminal History Background Checks (June 2006), at 51. The rise in people with criminal records may significantly be attributed to the increased arrests associated with the 'War on Drugs.'"

Source

Rodriguez, Michelle Natividad and Emsellem, Maurice, "65 Million Need Not Apply: The Case for Reforming Criminal Background Checks for Employment," National Employment Law Project, March 2011.