Preliminary Investigation as a Substantive Right: The Duterte v. Sandiganbayan Doctrine

The right to preliminary investigation protects every person from being rushed into trial on baseless charges. In Duterte v. Sandiganbayan, the Supreme Court ruled that this right is not a mere technicality but a substantive component of due process. When a prosecutor fails to observe it, the resulting criminal information can be dismissed — regardless of the merits of the accusation.

The case arose from graft allegations against then-Davao City Mayor Rodrigo R. Duterte and City Administrator Benjamin C. De Guzman over a computerization project. The Court did not rule on the truth of those allegations. It focused instead on a deeper question: whether the Ombudsman had respected the respondents' right to preliminary investigation before charging them.

What Preliminary Investigation Requires

A preliminary investigation is an inquiry to determine whether there is sufficient ground to believe that a crime has been committed and that the respondent is probably guilty, warranting trial. It is governed by Rule 112 of the Rules of Court and, for cases before the Sandiganbayan, by Administrative Order No. 07 (Rules of Procedure of the Office of the Ombudsman).

Section 4, Rule II of A.O. No. 07 prescribes the mandatory procedure: if the complaint is not under oath or relies only on official reports, the investigating officer must first require the complainant or witnesses to execute affidavits. Only after these sworn statements are secured may the officer order the respondent to submit counter-affidavits within ten days.

This procedure is adversarial by design. The respondent must be formally confronted with sworn accusations and given a real chance to rebut them. These steps are not optional.

What Went Wrong in the Ombudsman's Investigation

The complaint against Duterte and De Guzman was filed in 1990 by a concerned citizen, then followed by another complaint in 1991 from the Anti-Graft League-Davao City Chapter. Both involved the same computerization contract awarded to Systems Plus, Inc.

Instead of requiring complaint-affidavits and furnishing them to the respondents, the Graft Investigation Officer merely directed Duterte and De Guzman to submit comments on a dismissed civil case and a COA Special Audit Report. No sworn complaint-affidavit was ever presented to them at the outset.

Despite this flaw, an information was filed before the Sandiganbayan for violation of the Anti-Graft and Corrupt Practices Act. The respondents moved to quash, arguing that their right to preliminary investigation had been violated. The Sandiganbayan denied the motion, reasoning that the respondents could have filed motions for reconsideration with the Ombudsman, which supposedly cured the defect.

The Supreme Court's Ruling

The Supreme Court reversed. In a unanimous decision penned by Justice Kapunan, the Court held that the Ombudsman's procedure fell short of the requirements of A.O. No. 07. The order directing the respondents to comment on the civil case and audit report was not accompanied by a single affidavit charging them with any offense — a clear violation of the rules.

The Court also stressed that the comment stage under Section 2(b) of Rule II of A.O. No. 07 is distinct from, and precedes, the preliminary investigation stage under Section 4. Merely asking for comments does not constitute a proper preliminary investigation. The Court further noted an inordinate delay of four years between the respondents' submission and the Ombudsman's recommendation to file charges, which infringed on their right to speedy disposition of cases.

The petition was granted, and the criminal case was dismissed. The Court's core pronouncement:

"The right to preliminary investigation is not a mere formal or technical right; it is a substantive right. To deny the accused's claim to a preliminary investigation would be to deprive him of the full measure of his right to due process."

Practical Takeaways

• Insist on the proper procedure. A respondent in a preliminary investigation is entitled to receive the complaint-affidavits and supporting evidence before being required to respond. Being asked merely to comment on documents is not enough.
• Procedural defects can be fatal to a case. A flawed preliminary investigation can lead to the dismissal of charges, even if the underlying allegations appear serious.
• Delay matters. Inordinate delays in the conduct of preliminary investigation may violate the constitutional right to speedy disposition of cases.
• Legal counsel should scrutinize the process. Identifying irregularities early — such as missing affidavits or unjustified delays — can protect a client's rights and potentially end the case before trial.
• Rescission of a contract is not an automatic defense. While the fact that a contract was rescinded before charges were filed may be considered, it does not by itself absolve a person of graft liability.

This article is general information and not legal advice. For your specific situation, consult a lawyer or ask ASG Legal AI.