User blog comment:Abs.1998/Case No. 51 - Adam Bentley is the victim!/@comment-186.58.133.26-20131218013220/@comment-11738-20131218054745

Not sure about Serena, Lola, or Archibald, but I know that Howard and Martha will be involved. You'll have to wait until Thursday when the case is released.

Also, you need to already have gotten the Bronze and Silver Medals from Case 50 in order to unlock Case 51.