When the court deems it convenient it may order, immediately after the jury has been sworn, that one or more jurors be called as alternate jurors. The alternate jurors shall have the same qualifications, shall be subject to the same examinations and challenges as the regular jurors. Each side shall be entitled to one peremptory challenge against said alternate jurors. Alternate jurors shall take the same oath as the regular jurors and shall be considered for all purposes as members of the jury until discharged by the court.
Puerto Rico Legal Code