In January, New York City’s Board of Correction, which monitors conditions at Rikers Island, passed a new rule: prisoners under the age of 18 can no longer be sentenced to solitary confinement. Citing the detrimental impacts of isolation on young brains, the corrections department publicly touted the new protections.

But in the jail complex, the reality was much different. According to memos obtained by The Marshall Project, Rikers staff found a creative way around the rule: sentencing underage teens to solitary confinement and marking it as “owed time” to be served after their 18th birthdays. In one recent incident, a 17-year-old was sentenced to 20 days in solitary, with the punishment to be carried out when he entered the jail’s adult population. And he was not the only one. According to a letter dated May 22 from Bryanne Hamill, a member of the corrections board, to the corrections commissioner, Joseph Ponte, “this adolescent and many others” have received solitary sentences to be served after they turn 18.

Rikers has come under intense scrutiny over the past year, and the treatment of juveniles has been a major point of contention. Last August, Preet Bharara, the U.S. Attorney in Manhattan, released a 79-page report that described a “deep-seated culture of violence” perpetrated by guards against the jail’s youngest inmates. These teens are sentenced to solitary confinement at an “alarming rate and for excessive periods of time,” the report said. Soon after, the department announced that 16- and 17-year-olds would no longer be sentenced to solitary confinement, referred to officially as punitive segregation and colloquially as “the bing.”

But Brooklyn Defender Services, a public defender organization, said it found that the reforms were not being followed, and alerted Hamill and other members of the corrections board about a teenage client recently sentenced to time in isolation. This prompted Hamill to demand that the corrections department stop sentencing adolescents to solitary and to revoke any such punishments already ordered. Hamill was not immediately available for comment.

The letter from Hamill also noted dangerous conditions in the mental health unit at the adolescent jail, the Robert N. Davoren Center. “We observed multiple shards of tile scattered across the unit floor,” wrote Hamill to Ponte. “Many had sharp edges and could easily be used as weapons to harm others or themselves.”

When asked for a comment, a correction’s department spokesperson replied by email that, “no adolescent… [nor] 18-year-old has served a punitive segregation sentence for infractions committed at an earlier age” since the rules were changed. The spokesperson explained that any solitary sentences that may have been recorded had not been served, and that the Rikers staff had been instructed not to impose solitary on adolescents.

The department added that the broken tiles in the adolescent prison should be repaired this week, and that a policy ending solitary for 18-to-21 year olds is expected to be implemented by the end of 2015.