I found this Utica Observer-Dispatch article about the 1990 disappearance of Mark William Seelman. It seems he went missing together with another teen, Douglas Goodwin, who has never been found either. I hadn’t had any information about Douglas. The Charley file says he may have gotten into a car driven by an eighteen-year-old black male. Douglas was eighteen in 1990, but from the picture he appears to be white.
I will have to update Mark’s file, and add Douglas’s.