from a former poster--food for thought as at least a valid theory to work from--not saying it's the gospel, or the only way to go about it, but a case can be made from this viewpoint below, and shouldn't be dismissed--hmm, sort of matches Bittrolff(beinlich's daughter friends with melissa, woodworker, pickup:
.....And whenever a serial killer deviates from what he did in other cases, it means, there is something. Either he knew Barthelemy better than the other victims, was part of her wider environment or acquaintances or she reminded him of someone...
....A way to find him is to cross-reference Melissa Barthelemy's extended circle of acquaintances with owners of trucks, living in New York, working in construction jobs all over the country as freelancers or with freelancing groups. He is some kind of handycrafter, probably good with wood work and dry wall. Probably, he will live in the Bronx or a social similar area, but keep in mind, he is most time of the year not there. Also in the New York will be the secondary site where he kills his victims. This place is probably some workspace, maybe even with enough room to park his truck there and store the tools of his trade. Of course, he doesn't share the that place with others, nor will he let people in. Not because he has more bodies stored there, but because that is his inner sanctum, in a way.