P.R. Laws Ap. tit. 34A, § 1–A, Rule 6.10
Either the Prosecutor or the minor may file a sworn, written motion requesting the disqualification of the judge on any of the following grounds:
(a) That the judge has been Prosecutor or defense attorney of the minor.
(b) That the judge has ordered as a magistrate the apprehension, provisional detention or summons, or participated in the determination of probable cause to file a complaint.
(c) That the judge has a personal interest in the outcome of the case.
(d) That the judge has a preconceived opinion or prejudice for or against any of the parties, or that he has prejudged the case.
(e) That the judge is related, within the fourth degree of consanguinity or affinity, to the minor, the victim of the alleged offense or to the defense attorney or Prosecutor.
(f) That the judge is an essential witness in the case.
The judge whose disqualification is requested shall not entertain thereupon, and the motion therefor shall be argued before another judge.
Nothing provided heretofore shall preclude a judge from being disqualified motu proprio for any justifiable cause.