Could genetics help us understand mass killers?

In the wake of the Sandy Hook massacre, many are asking, did shooter Adam Lanza's genes make him a murderer?

In an opinion piece for the Hartford Courant, Nathaniel Comfort, associate professor in the Institute of the History of Medicine at Johns Hopkins, writes that in principle, genetics could identify a biological defect that could explain Lanza's shooting rampage. The problem, however, is that an accurate genetic explanation isn't simple—it would not pinpoint a single gene but would involve a complex profile of genes acting in combination with environmental factors:

Genetic science is well past the days of single genes for complex behaviors. The news media, however, are not. One blog asked, "Did Adam Lanza's genes make him a murderer?" The impression persists that, if we boil it down far enough, complex, nuanced, 21st-century genetics can provide our craving for simple, fundamental explanations as to why the incomprehensible continues to happen.