(1) In proceedings under this Part the opinion of -

(a) any member of the Garda Síochána, or

(b) any former member of the Garda Síochána,

who appears to the Court to possess the appropriate expertise (in this section referred to as the ‘appropriate expert’) shall, subject to section 74B, be admissible in evidence in relation to the issue as to the existence of a particular criminal organisation.

(2) In subsection (1) "expertise" means experience, specialised knowledge or qualifications.

(3) Without limiting the matters that can properly be taken into account, in the formation of such opinion, by the appropriate expert, it shall be permissible for that expert, in forming the opinion referred to in subsection (1), to take into account any previous convictions for arrestable offences of persons believed by that expert to be part of the organisation to which the opinion relates.

(4) Without prejudice to subsection (1), in proceedings under this Part the following shall be admissible as evidence that a particular group constitutes a criminal organisation -

(a) any document or other record emanating or purporting to emanate from the group or created or purporting to be created by the defendant -