The preliminary investigation entails a longer route. This affords both complainant and respondent chances to refute each other.

A fatally stabs B. No one witnesses the crime. B’s body is found at the crime scene only a week later. Police gather evidence that point to A. A criminal complaint is filed against him with the prosecutor’s office. This sets in motion a process called preliminary investigation. “Preliminary investigation is an inquiry or proceeding to determine whether there is sufficient ground to engender a well-founded belief that a crime has been committed and the respondent is probably guilty thereof, and should be held for trial (Section 1, Rule 112, Rules of Court).” In this instance, the prosecutor acting like a judge, determines based on evidence submitted to him, whether A is probably guilty of the crime charged. Note the phrase “probably guilty.” That means a finding that respondent seems to have committed the crime will suffice for the moment. With such probable cause, the prosecutor files the corresponding indictment with the court. The court now, is the one tasked, after weighing all pieces of evidence, to determine if respondent, now called accused, is guilty beyond reasonable doubt. If so, he is convicted. Otherwise, he is acquitted.

Now, what if in the same case, C, a policeman, actually witnesses A stabbing B? He right there and then arrests A and detains him at the precinct. Is a preliminary investigation necessary? Not anymore. Instead, an inquest ensues. It is “an informal and summary investigation conducted by a public prosecutor in criminal cases involving persons arrested and detained without the benefit of a warrant of arrest issued by the court for the purpose of determining whether or not said person should remain under custody and correspondingly be charged in court (Revised Manual for Prosecutors).” “When a person is lawfully arrested without a warrant involving an offense which requires a preliminary investigation, the complaint or information may be filed by a prosecutor without need of such investigation provided an inquest has been conducted in accordance with existing Rules (Section 6, Rule 112, Rules of Court).” Here the affidavit of the arresting officer attesting to actual stabbing of B by A will be enough. Based on this, the prosecutor can file the necessary information with the court, so the latter can pass judgment upon A.

See the difference between the two — preliminary investigation and inquest? The preliminary investigation entails a longer route. This affords both complainant and respondent chances to refute each other. When the complaint, via an affidavit, is filed, respondent is given an opportunity to file his counter-affidavit. The complainant will have a chance to rebut respondent’s counter-affidavit via a reply-affidavit. If the prosecutor allows, respondent will have the last say by filing a rejoinder-affidavit. Filing of affidavits is done at scheduled hearings the prosecutor sets. After this exchange, the fiscal evaluates the pieces of evidence adduced and determines existence of probable cause. Note that during this exercise, respondent is not detained.

In the inquest however, respondent is already in custody. With the affidavit of the person who personally witnessed the crime, chances are the fiscal will find probable cause. This no longer entails any exchange of affidavits. The prosecutor files the complaint with the court. The court proceeds to trial.

You more or less have an idea of how a criminal case is initiated. Please note that when the case is filed with the fiscal’s office, no warrant of arrest is issued. The prosecutor does not and has no power to issue that. This power is solely vested in the court. That is after the corresponding indictment from the fiscal is filed. And obviously, no complaint will be filed until after preliminary investigation. So, it takes time from the filing of the complaint with the fiscal to the issuance of the warrant.

Now you may ask, why is it that in an inquest, the respondent is already held in custody? That is because a warrantless arrest was made. A warrantless arrest can be done when as in the case above, the arresting officer himself witnesses the commission of the offense. The rules allow that the aggressor be apprehended immediately. When the complaint is filed by the prosecutor with the court, the accused can later on post bail for his temporary liberty pending final outcome of the case. But of course, this depends on whether the complaint is bailable or non-bailable.