As Dashiell Hammett once pointed out, murders, even in fiction, are not like mathematical problems. This hasn't, however, prevented plenty of other crime writers from treating them as if they were. In the equation are a few constants - the corpse, perhaps the time and cause of death - and a few unknown quantities. The detective isolates y and z by means of some rigorous and attentive sleuthing, and is then able, with a little lateral thinking, to deduce x: the identity of the murderer.

LRB 20 January 2005 | PDF Download