If a juror has any personal knowledge respecting a fact in controversy in a cause, he must declare the same in open court during the trial. If, during the retirement of the jury, a juror states a fact which would be evidence in the cause, as of his own knowledge, the jury must return into court. In either of these cases the juror making the statement must be sworn and examined as a witness in the presence of the parties and shall continue acting as juror unless the judge determines that if allowed to continue the trial would not receive an impartial consideration from the jury.
Puerto Rico Legal Code