P.R. Laws Ap. tit. 32A, § IV, Rule 77
2019-02-20 00:00:00+00
(A) The testimony of a subscribing witness is not necessary to authenticate a writing, unless otherwise provided by statute.
(B) If the testimony of a subscribing witness is required by statute to authenticate a writing and the subscribing witness denies or does not recollect the execution of the writing, the writing may be authenticated by other evidence.