Genetics In Court Is a Very Messy Business

The “my genes made me do it” defense is not solely reserved for Law and Order SVU. At least, not for long.

As science continues to tell us more and more about genetics, geneticists and medical ethicists believe it’s only a matter of time before people start using genetic predispositions to get them out of guilty verdicts. A precedent has been set with a number of recent cases, but scientists and lawyers alike flag that a poor understanding of genetics and behavior could result in a dangerous misuse of science in the legal system. That’s what Dr. Paul Appelbaum, the director of Columbia University’s Center for Research on Ethical, Legal and Social Implications of Psychiatric, Neurologic and Behavioral Genetics argues in an essay published today in the journal Neuron.

The problem is that a genetic predisposition for, say, violence, is not the same as a diagnosed mental disorder. “The ‘my genes made me do it’ argument is problematic because there is no evidence that genes make a person behave in a certain way that is beyond their capacity to control or recognize is wrong,” says Appelbaum. So far, studies on some of the leading genetic markers are only associational, and do not draw definite conclusions about a person’s behavior. Even if a person has a genetic mutation that puts them at a higher risk for cancer, there’s no guarantee they will develop the disease.

A genetics argument in criminal court may make scientists squeamish, and Appelbaum says that should apply to civil court—which handles things like divorce and some property damage cases—as well. An interesting case in Canada raised this red flag. In Adacsi v Amin, a woman named Tammy Adacsi sued her landlords after the house she was staying in caught on fire. She was hospitalized for months and claimed that her injuries prevented her from ever working again. The landlords demanded in court that Adacsi be ordered to submit a blood sample to test for whether she is a carrier of a gene mutation for Huntington’s Disease, which runs in her family. The landlords argued some of her symptoms could be a result of that disorder. The court ruled in their favor. Appelbaum says it’s not out of the question that a similar thing could happen in the U.S.

In the future, it might be even easier for courts to get access to defendants’ genetic data. “If it’s true that more and more of us will have our genomes sequenced, then this information will be sitting somewhere. It will be much easier for litigants in civil cases and prosecutors or defense attorneys in criminal cases to subpoena something that already exists,” says Applebaum. “The increased availability of this information in the future might spur its introduction into court.”

His recommendation is that courts allow genetics to enter arguments very, very slowly.