Case No. UKUT-00294-(IAC)

82. Professor Silke spoke to his central thesis in both examination in-chief and cross-examination. An exhaustive rehearsal of his testimony is not necessary. Professor Silke elaborated on the empirical data touched on in his report and also highlighted the low rates of psychiatric illness among politically motivated offenders. He further developed the discrete thesis of subjective altruism which features commonly in the psyche of such offenders. In addition, he elaborated on the distinction between “core” and “fringe” former members of a terrorist cell and the factor of an offender’s age – which, in this Appellant’s case – would fortify the low risk of reoffending thesis. 83. In cross-examination Professor Silke contended that his thesis is in no way undermined by either the standard “OASYS” model or the “Extremism Risk Guidance” (“ERG”) model. He testified that, in real terms, the reoffending rate for most convicted terrorists is in single figure percentages. He illustrated this by reference to empirical studies in different areas of the globe, in particular Northern Ireland and Sri Lanka. He further opined that, in an evolving national context, access to political power for former terrorists is not a key factor. Finally, he acknowledged that “one size does not fit all”. 84. The key elements of Professor Silke’s thesis were not challenged or contradicted by any competing expert evidence. They were probed appropriately in both cross-examination and questions from the bench. Professor Silke emerged as an impressive witness. His evidence was demonstrably balanced and well researched. Furthermore, his contention that he was advancing an orthodox thesis was not controversial. He engaged well with questions and there was no element of impermissible advocacy in his evidence. Overall, we accept the main tenets of his evidence.