Thank you for sharing this. Rumors like these are hard to sort through, but in a case that has gone unsolved for this long, even secondhand information can matter, especially if multiple people heard similar details from different sources.
If you believe you know who may have been involved, or if one of those people allegedly talked about their involvement to others, that is exactly the kind of information that should go directly to Warren Police or Warren County Crime Stoppers. Names, locations, dates, who said what, who else heard it, and how the information traveled are all important.
The Pennsylvania Avenue apartment basement rumor and the Kinzua Dam/well story are both very specific, so even if they turned out to be wrong, investigators may still want to know who was spreading those stories and why. Sometimes rumors are just rumors, but sometimes they come from someone trying to brag, misdirect, intimidate people, or test whether others know something.
The comment you mentioned from the hotline is disturbing, but it is also possible the person was reacting to information they could not discuss, speculation they had heard before, or something that was not meant to be interpreted literally. Either way, I can understand why that would stay with you.
If you still have the two names, I hope you call them in again, especially since the case remains open. I would include everything you remember, even if it feels messy or secondhand: the names, nicknames, addresses, who told you, when you heard it, who else was present, and whether anyone is still alive who heard the person allegedly admit involvement. Damien’s family deserves answers, and after all these years, a small detail from someone who thought they were only repeating an old rumor could still be the thing that helps.