Although White supremacist terrorists and Islamic fundamentalist terrorists share a hatred for Jews, the State of Israel, and the U.S. Government, there is no evidence that they have cooperated in planning and/or executing a terrorist attack in the United States. This question arises because Muslim inmates in Europe have recruited many fellow inmates to terrorist causes; for example, the group that conducted the Madrid train bombing began as a gang of previously unacquainted men jailed for minor criminal offenses in Spain. The investigation concludes that interactions in prison expose these men to Islamic extremism as a means of atoning for their previous sins. The current study was undertaken in late 2003 and early 2004, and a follow-up study was conducted in 2005. The study involved interviews with a number of academics, civil rights activists, law enforcement officials, and corrections officials. None of the individuals contacted knew of any situations in which there was any joint planning, operations, or alliances that involved White supremacists and Islamic fundamentalist terrorists. There may be a "copycat" factor operating, however, given the example of Timothy McVeigh, who targeted a building and its workers who symbolized the target of his hatred, i.e., the Federal Government. 49 references