Twenty years after DNA fingerprints were admitted by courts to link suspects to crime scenes, a new and very different class of genetic test is approaching the bench, reports the Washington Post. Rather than simply proving, for example, that the blood on a suspect’s clothes does or does not match that of a murder victim, “second generation” DNA tests seek to shed light on biological traits and psychological states of the accused. They allow genes to “testify” in ways never before possible, in resolving long-standing legal tangles or raising new ones.
Chemical companies facing “toxic tort” claims have persuaded courts to order DNA tests on people suing them to to show that the plaintiffs’ genes made them sick –not the companies’ products. In other cases, defense attorneys want judges to admit test results suggesting that their clients have a genetic predisposition for violent or impulsive behavior, adding a potential “DNA defense” to a legal system that until now has held virtually everyone accountable for their actions. Some gene tests are touted for their capacity to help judges predict the likelihood that a convict could break the law again — a measure of “future dangerousness” that raises questions about how far courts can go in anticipation of crimes that have not yet been committed. Most of these tests are still research tools hovering on the margins of admissibility. “So far, judges have been cautious,” said law Dean Karen Rothenberg the University of Maryland. She and others fear that judges and juries will fall too quickly for the new tests.