What is the test for determining whether a petitioner would pose an unreasonable risk to public safety?

Section 1170.126 provides that the trial court must exercise its discretion to determine whether a petitioner would pose an unreasonable risk of danger to public safety. ( 1170.126, subd. (f).) "Where . . . a discretionary power is statutorily vested in the trial court, its exercise of that discretion 'must not be disturbed on appeal except on a showing that the court exercised its discretion in an arbitrary, capricious or patently absurd manner that resulted in a manifest miscarriage of justice. [Citations.]' [Citation.]" (People v. Rodrigues (1994) 8 Cal.4th 1060, 1124-1125.)