With much fanfare, President Donald Trump signed the First Step Act into law in December. New Jersey senator and presidential candidate Cory Booker hailed the legislation as a milestone that marked a “meaningful break from decades of failed policies that led to mass incarceration.” Other supporters were more measured, characterizing it as a modest first step to keep the momentum going for criminal justice reform.

But the greatest sins of the First Step Act are not its modesty. The legislation nicks the edges of the carceral state while bolstering disturbing trends in criminal justice reform. CNN commentator Van Jones has claimed that the First Step Act is a “rare clean bill” that “does no harm.” Jones is wrong — it does much harm.

Grounding penal policy in the best evidence-based research is a mantra in criminal justice reform. Yet key provisions of the First Step Act are at odds with leading research on how to enhance public safety while minimizing social and economic costs and maintaining a fair criminal justice system that treats everyone — including people who are imprisoned — with dignity.