(1) Where identification evidence has been admitted, the judge shall inform the jury that there is a special need for caution before accepting identification evidence and of the reasons for the need for caution, both generally and in the circumstances of the case.
(2) In particular, the judge shall warn the jury that it should not find, on the basis of the identification evidence, that the defendant was a person by whom the relevant offence was committed unless—
(a) there is, in relation to the identification, at least one special circumstance that tends to support the identification; or
(b) there is substantial evidence, not being identification evidence, that tends to prove the guilt of the defendant and that the jury accepts that evidence.
(3) Special circumstance for the purposes of subsection (2) includes—
(a) that the defendant is known to the person who made the identification; or
(b) that the identification was made on the basis that the quality of the identification is good.
(4) Where—
(a) it is not reasonably open to find the defendant guilty except on the basis of identification evidence; or
(b) there are no special circumstances of the kind mentioned in subsection (3),
the judge shall direct that the defendant be acquitted.