(1) A person is presumed not to have been suffering from a mental impairment having the effect referred to in section 20(1) until the contrary is proved.
(2) The question whether a person was suffering from a mental impairment having the effect referred to in section 20(1)—
(a) is a question of fact; and
S. 21(2)(b) amended by No. 77/2005 s. 10(1).
(b) subject to subsection (4), is to be determined by a jury on the balance of probabilities.
(3) If the defence of mental impairment is raised by the prosecution or the defence, the party raising it bears the onus of rebutting the presumption.
S. 21(4) inserted by No. 77/2005 s. 10(2).
(4) If a person is charged with an indictable offence and, before the empanelment of a jury, the prosecution and the defence agree that the proposed evidence establishes the defence of mental impairment, the trial judge may hear the evidence and—
(a) if the trial judge is satisfied that the evidence establishes the defence of mental impairment, may direct that a verdict of not guilty because of mental impairment be recorded; or
S. 21(4)(b) amended by No. 68/2009 s. 97(Sch. item 39.18).
(b) if the trial judge is not so satisfied, must direct that the person be tried by a jury.