You're right as to JP, unless he made a sworn statement in a deposition as part of the investigation. Here's the applicable rule that @O.Incandenza alluded to (I think) expressing doubts similar to yours:My reply was related to any interviews JP did since he is now deceased but I do agree with any of Barry’s interviews
"Rule 804 - Hearsay Exceptions: Declarant Unavailable
(a) Definition of unavailability. "Unavailability as a witness" includes situations in which the declarant: ...(4) is unable to be present or to testify at the hearing because of death or then existing physical or mental illness or infirmity; ...
(b) Hearsay exceptions. The following are not excluded by the hearsay rule if the declarant is unavailable as a witness: 1) Former testimony. Testimony given as a witness at another hearing of the same or a different proceeding, or in a deposition taken in compliance with law in the course of the same or another proceeding, if the party against whom the testimony is now offered, or, in a civil action or proceeding, a predecessor in interest, had an opportunity and similar motive to develop the testimony by direct, cross, or redirect examination...."