Subscription to Death

Clarissa has a passion for murder mysteries, the paranormal, and serial killers.
When she discovers there's a subscription service where she can correspond with a make-believe serial killer, and be sent monthly evidence and clues to crack their case....she's all for it. Until suddenly the clues and evidence become a little too suspicious, and personal. Who is Clarissa dealing with? And how do they know so much? A knock at the back door will answer her questions, and instill new fears.