A system used to sentence offenders in Virginia, USA, increased sentences for Black and young defendants, according to a George Mason University and Texas A&M analysis reported by the Washington Post.

The study showed that defendants younger than 23 were 4 percentage points more likely to be incarcerated after the risk assessment was adopted, and that their sentences were 12 percent longer than their older peers. 

The researchers argue that part of the reason for the results is that judges did not follow the algorithm’s suggestions in most cases because they had not been trained to use the tool, said no alternative programmes had been available, or did not use risk scores when sentencing. 

"Virginia’s nonviolent risk assessment reduced neither incarceration nor recidivism; its use disadvantaged a vulnerable group (the young); and failed to reduce racial disparities," the study authors concluded.