University of Utah researchers are releasing a new study on sentences for convicted psychopaths.

SALT LAKE CITY — The sentence for a convicted psychopath is typically reduced by an average of one year when judges hear biological explanations for the criminal's psychopathy, according to a new study by researchers at the University of Utah.

The researchers say the study, to be published in the Aug. 17 issue of Science, illustrates a double-edged sword faced by judges who hear bio-mechanical explanations of mental disorder and then must decide whether psychopathy lessens a criminal's ability to tell right from wrong, or makes them more likely to commit crimes in the future.

"In a nationwide sample of judges, we found that expert testimony concerning the biological causes of psychopathy significantly reduced sentencing of the psychopath," James Tabery, the study's co-author, said in a prepared statement.

For the study, researchers surveyed 181 judges from 19 states based on a real-life Georgia case in which a psychopath was convicted of aggravated battery for beating a store clerk with a gun during a robbery. Researchers found that the hypothetical criminal was given a longer sentence than the average nine years for aggravated battery, but the sentence was also reduced from 14 to 13 years with an increase in listed mitigating factors when expert bio-mechanical testimony was heard.

In the study, psychopathy is defined as "a clinical diagnosis defined by impulsivity, irresponsibility, shallow emotions, lack of empathy, guilt or remorse, pathological lying, manipulation, superficial charm and the persistent violation of social norms and expectations."

Benjamin Wood