Roscoe's Keys are an item in The X-Files: Resist or Serve. Theses keys allow you to unlock the back door of J.J.'s Diner, which is the only way you can escape the diner after the front door was blockcaded by a zombie. These keys can be obtained from Roscoe, but only when he becomes a flesh eating zombie. After killing him, collect the keys to unlock the back door to the diner.