I would be mega-delighted to become a character in your story. If it can be done plausibly, you can say that your characters meet the ACTUAL me, by name, Joseph Ravitts, U.S. Navy Retired.
I confess that I have not read your mystery, at least not up to date; I may have looked early on. If your characters are, or could be, in Colorado, Illinois, Wisconsin, Missouri, Maryland, New York or Connecticut, a rationale could be devised for them to meet me in person.