The brave new world of genomics, spurred on by the Human Genome Project, presents tantalizing possibilities for developments in criminal law as well as advances in medicine and understanding disease. DNA identification testing has become commonplace in the courts, transforming the criminal justice system, demonstrating innocence, and identifying perpetrators. Already it is clear that DNA testing will be used as a way of predicting which medical treatments will be effective. With predictive medicine becoming a reality, surely predicting human behavior cannot be far behind.
The link between crime and genetics is hardly a new idea. Since at least the late nineteenth century, courts and prisons have reflected attempts to discriminate between the innately criminal and those who acted merely by force of circumstance, whose crimes would not pose a future danger to society. (1) To aid this distinction, predictions of future dangerousness became vital to the criminal justice system. This legacy has persisted despite the enactment of civil rights legislation that did away with the more overtly racist laws derived from eugenics. As a result, predictions of future dangerousness now dominate death penalty sentencing determinations and the commitment proceedings of sexually violent predators. (2)
Surprisingly, although the stakes are high for their subjects, the predictions receive little judicial or legislative scrutiny. Courts and legislatures are well aware of the unscientific nature of these predictions; nonetheless, they continue to demand them. (3) Responding to this continued demand, researchers have attempted to improve the accuracy of their predictions of future dangerousness by developing actuarial instruments to assess the risk of repeated violence in offenders and psychiatric patients by examining a number of factors, scored on a scale with points varying according to the particular instrument. (4) Each instrument evaluates different risk factors, and scores each differently. No one method is particularly predictive; (5) but the general consensus is that such instruments are superior to clinical judgment alone. (6) Whether future dangerousness predictions can meet standards of scientific validity, and what, if anything, can be done to improve them, are highly debatable issues. (7) The question posed by behavioral genetics is whether molecular biology can improve this record.
Genetic information, including behavioral genetics, has exploded under the influence of the Human Genome Project. (8) Virtually everyone agrees that genes influence behavior. (9) Scandinavian studies of adopted twins are widely touted as supporting the role of genes in crime. (10) That the cycle of violence is repeated across generations is common knowledge. (11) Recently, alleles of specific genes, like those transcribing for monoamine oxidase A (MAOA), have been identified and linked with propensities to violence. (12) Should adding genetic information to the mix not produce more accurate predictions of future dangerousness?
This question must be answered with a qualified yes and no. First, there is unfortunate history in this regard, and while we might wish to put the bad old days behind us, the shocking absence of scientific scrutiny for eugenics assertions has managed to persist in the astonishing failure of courts and legislatures to examine the scientific validity of expert future dangerousness predictions. (13) Throwing away the key when someone has committed a grisly crime is an all-too-human response to the specter of tragedy and nasty headlines. But it is precisely to counter such responses that we have the rule of law. Inquiry into the relevance and reliability of proffered evidence is a foundational aspect of this process.
Second, although information from the biology of violence, including genomics, could vastly improve the way predictions are made, such information must be tested, scrutinized, and properly limited so that the promise of science is not once again perverted into the cynicism of political expediency. …