Look behind you : a novel / Iris Johansen and Roy Johansen.
"A serial killer is on the loose in San Diego, and he has a most unusual M.O.: With each kill, he leaves behind objects with unclear meanings. Most of the recent killings are centered near Kendra Michaels' home and office, so it comes as no great surprise when the FBI shows up at her door....
New York :
St. Martin's Press,
by: Ostrander, Isabel, 1883-1924.
by: Kellerman, Jonathan,, et al.