IN WARDIUS V. OREGON, THE COURT STRUCK DOWN ENFORCEMENT OF AN OREGON NOTICE-OF-ALIBI STATUTE AGAINST THE DEFENDANT IN THE ABSENCE OF RECIPROCAL DISCOVERY AS VIOLATIVE OF DUE PROCESS. WARDIUS AND ITS EFFECT ON ALIBI EVIDENCE IS DISCUSSED IN RELATION TO THE DUE PROCESS RECIPROCITY DECISION, RECIPROCITY AND THE PROSECUTOR'S FORMAL DISCOVERY, AND RECIPRICITY AND THE PROSECUTOR'S INVESTIGATIVE DISCOVERY. IT IS SUGGESTED THAT BY NOT LIMITING DEFENSE DISCOVERY TO THE SUBJECT MATTER OF THE INVESTIGATIVE DISCOVERY, THE RECIPROCITY PRINCIPLE IN WARDIUS CAN FORM THE BASIS FOR FULL FILE DISCLOSURE IF ANY INFORMATION IS GIVEN TO THE PROSECUTION BY THE DEFENDANT. IN GAGNON V. SCARPELLI, THE COURT RULED THAT THE PRELIMINARY HEARING PROCEDURAL PROTECTIONS MANDATED FOR PAROLEES IN THE 1972 DECISION OF MORRISSEY V. BREWER MUST LIKEWISE BE PROVIDED IN THE PRELIMINARY HEARING GIVEN A PREVIOUSLY SENTENCED PROBATIONER. THE PRELIMINARY OR PROBABLE CAUSE HEARING, WHEN PROVIDED, IS THE STAGE OF THE CRIMINAL PROCESS THAT SUPPLIES A DEFENDANT WITH HIS ONLY PRETRIAL OPPORTUNITY FOR COMPULSORY PROCESS TO INTERROGATE UNWILLING WITNESS, TO TALK TO HIM VOLUNTARILY, THAT IS, FOR DEPOSITIONS. YET WITHOUT A PRELIMINARY HEARING, THE PROCEDURAL SAFEGUARDS REQUIRED BY GAGNON AND MORRISSEY FOR PROBATION AND PAROLE REVOCATION ARE NOT PROVIDED A CRIMINAL DEFENDANT. THE AUTHOR CONTENDS, THEREFORE, BY EXTRAPOLATION, THAT BECAUSE OF THE CONSTITUTIONAL DEFICIENCIES OF SECRET GRAND JURY PROCEEDINGS (IN TERMS OF THE MINIMAL ATTRIBUTES OF A DUE PROCESS HEARING), A PRELIMINARY HEARING WITH THE FULL TRAPPINGS OF DUE PROCESS MUST BE PROVIDED IN ADDITION TO - OR INSTEAD OF - THE GRAND JURY PROCEEDING.