G.R. No. L-33125, September 30, 1971
IN THE MATTER OF THE PETITION OF ROMAN DE ASIS FOR A WRIT OF HABEAS CORPUS. ROMAN DE ASIS, petitioner, vs. THE HON. HONORIO ROMERO, Presiding Judge, Court of First Instance of Pampanga, Branch III; THE HON. ANTONIO G. P. FAUSTO, Assistant Provincial Fiscal of Pampanga; and THE PROVINCIAL WARDEN OF THE PROVINCE OF PAMPANGA, respondents.

FACTS

Petitioner Roman de Asis was charged with the crime of slight physical injuries. After he pleaded not guilty, the prosecution filed a motion for leave to amend the information to charge the graver offense of serious physical injuries. The petitioner opposed this amendment, arguing it would deprive him of a preliminary investigation for the new, more serious charge. The trial court granted the prosecution’s motion to amend the information. Consequently, the petitioner filed a petition for a writ of habeas corpus, contending that his detention became unlawful due to the court allowing the amendment without first conducting a preliminary investigation for the amended charge of serious physical injuries.

ISSUE

The core issue is whether a court can grant the prosecution’s motion to amend an information to allege a graver offense, after the accused has pleaded not guilty to the original lesser charge, without first conducting a new preliminary investigation specifically for that graver offense.

RULING

The Supreme Court dismissed the petition, ruling that the amendment of the information was proper and did not necessitate a new preliminary investigation. The legal logic is anchored on the distinction between a preliminary investigation and a preliminary examination. A preliminary investigation is a prosecutorial function to determine probable cause for filing an information, and it is not a constitutional right but a statutory privilege that can be waived. In contrast, a preliminary examination is a judicial function required by the Constitution before an arrest warrant can be issued. The Court held that the right to a preliminary investigation is not a fundamental right and can be waived expressly or impliedly.
In this case, by pleading not guilty to the original charge and actively participating in the trial, the petitioner was deemed to have waived his right to a preliminary investigation for the amended charge. The amendment was considered formal, as it arose from the same facts and circumstances alleged in the original information for slight physical injuries. The Court further reasoned that allowing the amendment promoted judicial efficiency. Disallowing it would have forced the prosecution to file a separate information for the graver offense, a procedural step that settled jurisprudence permits without placing the accused in double jeopardy for the lesser charge. Therefore, the petitioner’s continued detention under the amended information was lawful.