What's ahead in the series

On the Trail of a Killer

Sunday: Aurora Police Chief Frank Michels investigates the apparent murder of well-known florist Warren Lincoln. Lincoln, his wife, Lina, and brother-in-law, Byron Shoup, are all missing.

Monday: Tests show blood found at Lincoln's home belongs to a man suffering from a disease.

Tuesday: Michels listens to a bizarre story about a kidnapping.

Wednesday: A strange letter leads police to one of the missing.

Thursday: The suspect confesses, but details soon begin to change.

Friday: Police figure out what really happened at Warren Lincoln's greenhouse.

Saturday: Michels and the Kane County state's attorney square off in court.

Sunday: A special Web-only conclusion -- What happened to the heads?