The probation officer's investigation of the offense usually begins with an examination of the complaint, information, or indictment charging the defendant and the docket describing the judicial history of the case. These documents may be found in the district court clerk's file. The officer will use them to develop a brief chronological history of the prosecution of the case and identify the specific charges that resulted in the conviction. The review of the clerk's file may also reveal the identities of co-defendants or related cases, the status of which must be investigated and reported in the presentence report. At the same time, the probation officer may also request information about the offender's history, circumstances, and release status from the pretrial services officer or from a separate pretrial services agency.