Rikers Island. Photo: Emmanuel Dunand/AFP/Getty Images

New York City Mayor Bill de Blasio announced on Tuesday that the city would stop using solitary confinement on inmates under 21 at local jails.

In an op-ed in the Gotham Gazette, New York City correction commissioner Joseph Ponte described the move as “an unprecedented milestone in New York State correctional history” and “across the nation,” claiming that “no other city or state has accomplished comparable punitive-segregation reforms.”

Tuesday’s decision comes at the end of a long process of prison reform and much public criticism and outrage. In 2014, facing widespread anger over violence and the treatment of young offenders in city jails — and a suit from the federal government over the deplorable conditions at Rikers Island — the New York Department of Corrections (DOC) agreed to stop using punitive segregation — solitary confinement — on inmates who are 16- and 17-years-old. This summer the age limit was raised to 18.

City officials repeatedly voted to raise the cut-off for solitary confinement to 21, and moved to ban solitary confinement for anyone under 21 years of age at Rikers, to much fanfare, in January 2015. But until Tuesday’s announcement, the DOC routinely pushed to extend the deadline. As late as July 2016 there were still 16 inmates between the ages of 19 and 21 in solitary confinement at Rikers.

In Tuesday’s announcement Ponte said that the decision came after a long process of testing and experimentation: “Our ending of punitive segregation today is founded upon thoughtful evaluation, flexibility, and adjustments with the needs and safety concerns of staff and young adults front and center.”