Preliminary InvestigationPreliminary Inquiry
conducted by the prosecutorconducted by the judge
to ascertain whether the alleged offender should be held for trialto determine probable cause for the issuance of a warrant of arrest
executive in naturejudicial in nature


● There is a distinction between the preliminary inquiry which determines probable cause for the issuance of a warrant of arrest and the preliminary investigation proper which ascertains whether the offender should be held for trial or be released. The determination of probable cause for purposes of issuing the warrant of arrest is made by the judge. The preliminary investigation proper whether or not there is reasonable ground to believe that the accused is guilty of the offense charged is the function of the investigating prosecutor. (AAA vs. Carbonell, G.R. No. 171465, June 8, 2007)

●Preliminary investigation should be distinguished as to whether it is an investigation for the determination of a sufficient ground for the filing of the information or it is an investigation for the determination of a probable cause for the issuance of a warrant of arrest. The first kind of preliminary investigation is executive in nature. It is part of the prosecution's job. The second kind of preliminary investigation which is more properly called preliminary examination is judicial in nature and is lodged with the judge. (Co vs. Republic, G.R. No. 168811, November 28, 2007)