CTSAs are part of the government’s policy for combatting terrorism which is overseen by the Office for Security and Counter Terrorism (OSCT).214 The policy is known as CONTEST.215 There are four strands to CONTEST: Protect, Prepare, Pursue and Prevent.216 CTSAs are concerned with the Protect and Prepare strands and are accredited by and work with the National Counter Terrorism Security Office (NaCTSO) which is part of Counter Terrorism Policing. NaCTSO inform and oversee the work of Protect and Prepare.217
The relationship between OSCT, NaCTSO and other parts of the national framework for countering terrorism is set out below in Figure 10.
Figure 10: The relationship between OSCT, NaCTSO and other parts of the national framework for countering terrorism218
NaCTSO is concerned, amongst other things, with providing advice and guidance around protective security for “crowded places”.219
In providing that advice and guidance, NaCTSO supplies videos, written documents and sets up exercises which are provided to the private sector and to the public by CTSAs.220 CTSAs also provide advice and guidance to some individual sites in relation to what steps can be taken to reduce their vulnerability and prepare for potential terrorist attacks.221 There were insufficient CTSAs to provide that advice to all crowded places on an individual basis.222 The process to qualify as a CTSA takes approximately two years.223 CTSAs are the most highly trained counter-terrorism advisors in the country.224 I accept that those who dealt with the Arena were highly trained and highly skilled.225
The basis on which sites were selected to receive advice has altered over the years. From about 2008, sites were selected on the basis of their vulnerability. In 2014 that changed, and sites were selected on the basis of their attractiveness to terrorists.226
Under the new attractiveness scheme, there are three tiers. The Arena was graded Tier 2(b): the “2” indicates that the Arena, “whilst not of national or international prominence, nevertheless has a profile above local or have a significant attendance by notable users (albeit infrequent, irregular or unpredictable)”;227 the “(b)” indicates that at the time of designation the Arena had “a more developed security stance.”228