The Fregoli Delusion — Michael J. McCann

When the only eyewitness to the murder of a billionaire suffers from a rare psychotic disorder that causes a delusional misidentification of people, Lieutenant Hank Donaghue must search for evidence of the killer among the wealthiest members of Glendale's social class - including close friends of his own mother. Detective Karen Stainer, on the other hand, firmly believes that the eyewitness was not delusional and is telling the truth when he identifies the killer as the man he believes is persecuting him!