P.R. Laws Ap. tit. 32A, § III, Rule 24.1
(a) Petition. — A person who desires to perpetuate his own testimony or that of another person regarding any matter that may be cognizable in court may file a verified petition to that effect. The petition shall be entitled in the name of the petitioner and shall show:
(1) That the petitioner expects to be a party to an action cognizable in court but is presently unable to bring it or cause it to be brought;
(2) the subject matter of the expected action and his interest therein;
(3) the facts which he desires to establish by the proposed testimony and his reasons for desiring to perpetuate it;
(4) the names or a description of the persons he expects will be adverse parties and their addresses so far as known; and
(5) the names and addresses of the persons to be examined and the substance of the testimony which he expects to elicit from each.
(b) Notice. — After the petition is filed, the petitioner shall serve a notice upon each person named in the petition as an expected adverse party. The notice shall be served in the manner provided in Rule 4.4 for service of summons, and a period of not less than fifteen (15) days shall be allowed for the parties so served to raise any objections to the petition; but if such service cannot with due diligence be made upon any of the persons named in the petition, the court may make such order as is just for service by publication or otherwise, and shall take such measures as are appropriate to safeguard the interests of persons who have not been notified. If any of the persons is a minor or incompetent, the provisions of Rule 15.2 shall apply.
(c) Order and examination. — If the court is satisfied that the perpetuation of the testimony may prevent a failure or delay of justice, it shall make an order designating or describing the persons whose depositions may be taken and specifying the subject matter of the examination and whether the depositions shall be taken upon oral examination or written interrogatories. The depositions may then be taken in accordance with these rules and the court may make orders of the character provided for by Rules 31 and 32. For the purpose of applying these rules to depositions for perpetuating testimony, each reference therein to the court in which the action is pending shall be deemed to refer to the court in which the petition for such deposition was filed.
(d) Use of deposition. — If a deposition to perpetuate testimony is taken under these rules or if, although not so taken, it would be admissible in evidence in the courts of the jurisdiction in which it is taken, it may be used in any action subsequently brought involving the same subject matter, in accordance with the provisions of Rule 29.1.