In his 1891 book, The Man of Genius, Cesare Lombroso, an Italian physician, provided a gossipy and expansive account of traits associated with genius—left-handedness, celibacy, stammering, precocity, and, of course, neurosis and psychosis—and he linked them to many creative individuals, including Jean-Jacques Rousseau, Sir Isaac Newton, Arthur Schopenhauer, Jonathan Swift, Charles Darwin, Lord Byron, Charles Baudelaire, and Robert Schumann.
Lombroso speculated on various causes of lunacy and genius, ranging from heredity to urbanization to climate to the phases of the moon.
In his 1869 book, Hereditary Genius, Galton used careful documentation—including detailed family trees showing the more than 20 eminent musicians among the Bachs, the three eminent writers among the Brontës, and so on—to demonstrate that genius appears to have a strong genetic component.
Prosecuted under Federal law that allows for death penalty in the course of a carjacking or kidnapping. Only received death sentence for two murders in Massachusetts, life for New Hampshire killing.
The murder took place in Michigan, which does not have the death penalty, but the body was found in Manistee National Forest, which is federal land.
On appeal, his defense team argued that they should consider any reasonable doubt they have that the murder took place outside of the forest before being moved into the forest after death, which would make him ineligible for the death penalty.
Duncan was convicted of the 2005 kidnappings and murders of members of the Groene family and sentenced to three death sentences and three life sentences.
He is also serving 11 life sentences in conjunction with the same crimes as well as the 1997 murder of Anthony Martinez of Beaumont, California.