The Court held in First Women’s Credit Corporation v. Perez that:
It is settled that the determination of whether probable cause exists to warrant the prosecution in court of an accused should be consigned and entrusted to the Department of Justice, as reviewer of the findings of public prosecutors. The court’s duty in an appropriate case is confined to a determination of whether the assailed executive or judicial determination of probable cause was done without or in excess of jurisdiction or with grave abuse of discretion amounting to want of jurisdiction. This is consistent with the general rule that criminal prosecutions may not be restrained or stayed by injunction, preliminary or final, albeit in extreme cases, exceptional circumstances have been recognized. The rule is also consistent with this Court’s policy of non-interference in the conduct of preliminary investigations, and of leaving to the investigating prosecutor sufficient latitude of discretion in the exercise of determination of what constitutes sufficient evidence as will establish probable cause for the filing of an information against a supposed offender.
While prosecutors are given sufficient latitude of discretion in the determination of probable cause, their findings are subject to review by the Secretary of Justice. (Emphasis supplied)
And it held in UCPB v. Looyuko:
Consistent with this policy, courts do not reverse the Secretary of Justice’s findings and conclusions on the matter of probable cause except in clear cases of grave abuse of discretion.
x x x x
In other words, judicial review of the resolution of the Secretary of Justice is limited to a determination of whether there has been a grave abuse of discretion amounting to lack or excess of jurisdiction considering that full discretionary authority has been delegated to the executive branch in the determination of probable cause during a preliminary investigation. Courts are not empowered to substitute their judgment for that of the executive branch; it may, however, look into the question of whether such exercise has been made in grave abuse of discretion. (Emphasis and underscoring supplied)