The classic security force problem throughout the troubles was that they believed that through their intelligence agencies they knew a great deal about who the leaders of paramilitary groups were, and who had ordered or carried out many killings and other offences. As in other countries, however, their difficulty lay in converting intelligence into evidence which would stand up in a court of law. The supergrass tactic seemed to offer a mechanism for achieving this. As time passed, however, the legal and political controversy grew and judges became more cautious about convicting.
