For nearly 50 years, Harvard was haunted by an unsolved murder. DNA now points to a serial rapist.

It is a winter-swept afternoon in January 1969, the thermometer dangling in the mid-30s in Cambridge, Mass. A Harvard University graduate student named James Humphries hustles up the stairs to the top floor of an apartment building two blocks from Harvard Square.
His friend and classmate Jane Britton was a no-show at an important exam that morning. The phone just rang and rang when he called to check in, a police report would later document. With his knocks now going unanswered at the gold-painted door leading into the $75-a-month apartment Britton shares with a pet cat and turtle, he tries the handle. It’s unlocked.