SOMERVILLE, MA—Drew Engel, 27, can point to his roommate’s fingernail or toenail clippings in every single room of his apartment with relative ease.National News Highlights • Local • ISSUE 48•44 • Oct 31, 2012 0341SOMERVILLE, MA—Drew Engel, 27, can point to his roommate’s fingernail or toenail clippings in every single room of his apartment with relative ease.