PRELIMINARY INVESTIGATION. - It is the activity intended to submit, from the evidentiary standpoint, to the judge's examination the material of cognition necessary for the determination of the suit.
This activity presents itself as a genuine collaboration between the judge, who has the power-duty to take the evidence, and the litigating parties, upon whom, as a rule, the burden of the evidentiary initiative falls.
While reserving the notions concerning the definition, the distinctions and the evaluation of evidence (v. PROCESSO), the examination of the i.[instruction] is here limited to those elements that belong to the mechanics of procedure.
The taking of evidence must normally be done in the so-called evidentiary period, which opens ex officio after the litis contestatio (CIC, can. 1371, no. 2) and closes with the conclusio in causa (can. 1860 § 1).
Before the litis contestatio the evidence cannot be taken except for exceptional reasons indicated by the CIC (can. 1730), whereas after the conclusio in causa this is permitted only for cases in which the judgment is not susceptible of becoming res judicata, in cases of legitimate impediment (can. 1861 § 1).
Within the evidentiary period the judge assigns to the parties, by his own decree, a suitable term within which they must offer the judicial proofs that they believe it in their interest to provide; this term is directory and as such may be extended by the judge at the request of the parties. The taking of evidence concerns naturally only the proofs that are declared or simply held admissible and relevant. The same judge charged with taking them — whose figure, in the case of a collegiate tribunal, has as a rule its own independence — decides in a preliminary manner on the admissibility of the proofs, and should controversies arise in the matter, these will be decided according to the forms of the incidental procedure. Such a preliminary judgment on the admissibility of the proofs, whether it be made by the examining judge or conversely (which happens rarely) by the judge who must decide the merits, does not however exercise — even where it has manifested itself in the form of a jurisdictional measure on account of the incidental issue that arose — any influence on the evaluation of their results. The proofs must be provided by the party with its own means and not with means belonging to the adversary; the latter, however, may have recourse to them when the matter is common to both parties (e.g., can. 1822).
On the admissibility of proofs, can. 1749 is to be borne in mind, according to which the judge has the power to reject proofs whose admission would cause excessive prolongation of the trial, giving preference to those of prompt execution, unless they are necessary because of the manifest influence of those already obtained (cf. cann. 1754-62). In this matter the concern of the canonical legislator is always alive, since he is anxious that disputes be decided by the judge in the shortest possible time (can. 1731 § 2). The initiative in the taking of evidence, however, is not always that of the parties; as will be seen, in fact, certain determined means are established directly by the judge (cann. 1806, 1832).
When it belongs to the party, the latter requests, by a specific judicial petition, the admission of the evidentiary means in which it has an interest, and the judge, having heard the other parties and having resolved, if need be, every specific incidental question, grants or rejects the petition by his own decree, which must be notified to the opposing party.
The rules on the taking of evidence apply to proofs constituted in the course of the trial, it being sufficient for pre-constituted ones that the parties make direct exhibition of them at the chancery of the tribunal. Once the proof has been admitted, as regards its carrying out, the widest powers are reserved by canon law to the judge charged with it, since, among other things, the private parties do not attend the conduct of such procedural activities.
As a rule the proofs are gathered in the courtroom of the tribunal, unless their nature (e.g., judicial inspection) makes it necessary to carry them out elsewhere, in one or more sessions, with separate records which must be — as regards the part concerning their intervention — read to the interested parties and signed by them.
Bibliography5 works
Ferdinando della Rocca