P.R. Laws Ap. tit. 34A, § II, Rule 186
(a) During the trial.— Once the trial has begun, and before the verdict or judgment is rendered, if the judge before whom the defendant was tried is unable to continue with the trial on account of death, sickness or other disability or for termination of office, any other judge of the same category regularly sitting in or assigned to the court may perform said duties, provided he certifies, within reasonable time after his appointment that he has become familiar with the documents and record of the case.
(b) After the verdict or conviction.— If by reason of termination of office, death, sickness or other disability, the judge before whom the defendant was tried is unable to discharge the duties to be performed by the court after the verdict or conviction, any other judge regularly sitting in or assigned to the court may perform said duties.
(c) Jury trials and court of law.— The substitution referred to in subsection (a) of this rule shall only be carried out in cases of jury trials. By agreement of the parties, there can be a substitution of judge before the judgment in those cases being tried by a court of law.
(d) Appointment of the substitute judge.— The substitute judge should be appointed by the administrative judge of the court to which the first judge belonged, or in lieu of, by the Chief Justice of the Supreme Court, within two (2) days after notice of the judge’s disability has been received.
(e) Authority of the substitute judge.— The substitute judge shall have the same power, authority, and jurisdiction in the case as if it should have begun before him.
(f) Duty of the secretary.— In those courts where there is only one judge assigned, the secretary of the court, immediately after he knows about the judge’s disability shall:
(1) Forthwith advise immediately to the Court Administrator and the Chief Justice of the Supreme Court.
(2) Summon the parties for the setting of a date that in no case shall be less than ten (10) days nor more than fifteen (15) days.
(g) New trial.—
(1) If the substitute judge becomes convinced that he cannot continue performing the duties of the former judge, he may in his discretion, grant a new trial.
(2) The impossibility of complying with the procedure provided by this rule, not attributable to the defendant, shall constitute grounds for a new trial.
History —July 23, 1974, No. 145, Part 1, p. 670.