Yeah, that only three were wrapped in burlap is new information to me. Both Robert Kolker's article and the book he wrote, Lost Girls, say all four of that cluster of burials were in burlap. Amber, Megan, Melissa, Maureen. Obviously, he thought that was true when he wrote it, but that's another thing that's been kept back until now by LE that they've obviously known since the burials were first uncovered.
Five dead women turn up on a beach, and their families ask: Who murdered my daughter? Who was my sister — really?
nymag.com
I suppose the question is, was one buried without wrapping, or was one wrapped in a different kind of material?
There is another victim on the LISK wiki page, where it mentions she was wrapped but that LE will not give information about the material. Makes me wonder if it's burlap, too, or something very distinctive or unique. She was found in 2013. She is unidentified.
en.wikipedia.org
MOO