Call the Police - The Case of the Unknown Strangler

Miss Francine Ably, a 47 year old voice teacher, was just sitting down to dinner when her doorbell rang.  Thinking it may be someone interested in singing lessons, she opened the door and invited the man in to her home.  That was the last thing she did. The police found her body two hours later, but could not find any motive for the crime. Fifty six hours later, and aged lawyer named Joe Crocker was climbing the steps to his apartment when he found someone waiting for him at his door.  He soon became the strangler's second victim.  Again, there was no motive.  Soon, the deeds of the unknown strangler made the newspaper headlines.