The most wanted terrorist on the planet at the time of writing, Ayman al-Zawahiri, the current leader of Al Qaeda, is a former extremist prisoner. He was arrested and imprisoned in Egypt in the early 1980s because he had links with the assassins of the Egyptian President Anwar Al Sadat. Within the prison world, the important groups are ordinary decent prisoners who have been radicalised within prison, possibly as a result of contact with extremist prisoners. These converts to the cause are distinctive because their prior behaviour outside had no political involvement whatsoever, and thus risk assessment processes with some of these prisoners may be unaware that extremism is even an issue. One problem with many models of risk assessment is that they tend to focus more on factors linked with individuals becoming terrorists and often largely ignore factors associated with individuals leaving terrorism.