The Genius by Jesse Kellerman
In a decaying New York slum, a tenant named Victor Cracke has disappeared, leaving behind countless cardboard boxes of strange, original artwork. Gallery owner Ethan Muller can see their brilliance--and their moneymaking potential. Strictly speaking, the drawings don't belong to Ethan. But great art demands an audience, and before long Ethan's wildly successful show is being covered by the Times...where it attracts the attention of the police. Because the subjects of the pictures look exactly like the victims in a long-cold murder case. Ethan has received a letter saying stop stop stop. And the still-missing genius may be the link to a madman--or the madman himself.