Concern has been expressed that prisoner radicalization poses a high probability threat to the safety of the United States. Although the threat of terrorist acts planned in prison is known to be above zero because of a nearly executed terrorist plot hatched in a state prison, the central finding of this research is that the actual probability is modest. The reasons for a modest probability are fourfold: Order and stability in U.S. prisons were achieved during the buildup period, prison officials successfully implemented efforts to counter the “importation” of radicalism, correctional leadership infused antiradicalization into their agencies, and inmates’ low levels of education decreased the appeals of terrorism.
Useem, Bert, and Obie Clayton. 2009. "Radicalization of U.S. Prisoners." Criminology & Public Policy (August): 561-592. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-9133.2009.00574.x