By the end of this year, the New York City Department of Corrections will end a longstanding practice, solitary confinement of adolescents, in which 16- and 17-year-old inmates are locked in a cell for more than 23 hours a day without any human contact for months.

Commissioner Joseph Ponte made the announcement late last month in an internal memo to Mayor Bill de Blasio that was obtained by the New York Times. Ponte said his watchdog agency, which oversees city jails, will instead execute alternative penalties and focus more on prevention.

“What we’re struggling with is we’re still operating with adult policies,” he said in the memo. “You have the commitment of this agency, and my own personal commitment, to drastically improve the level of safety and services offered to adolescents at Rikers Island.”

When Ponte took office in April, he promised to enact reform measures. He highlighted in the memo that he has expanded educational programs, with more emphasis on vocational training, and the use of force against adolescent inmates has declined from 28 incidents in April to 18 in August. Ponte said he is in the process of changing rules that mandate how solitary confinement is used at the facility.

At Rikers Island, the nation’s second largest jail system, there are approximately 300 adolescents among the approximately 11,500 inmates. Some 530 inmates are reportedly in solitary confinement daily. Fifty of those inmates are teens. According to advocates and city elected officials, the majority of teen inmates have not been convicted of any crime and are awaiting trial.

The announcements came amid growing scrutiny and reports from relatives of inmates and jail reformers about the brutal treatment of inmates at Rikers Island, particularly adolescents and those who have mental illnesses.

In early August, U.S. Attorney Preet Bharara sent a scathing report to de Blasio about the “deep-seated culture of violence, rampant use of unnecessary excessive force” and inequitable use of solitary confinement against adolescent inmates at Rikers Island.

Bharara stated that jail officers violate teen inmates’ constitutional rights by routinely abusing them violently. He said this abuse is a result of former Mayor Mike Bloomberg administration’s failure to oversee and reform the correctional facility. Bharara recently promised to take legal action against the city if the de Blasio administration does not impose reform measures.

Weeks after Bharara’s report, the New York City Council passed a bill, which was approved by de Blasio, to track and limit the use of solitary confinement at the correctional facility. The City Council also passed a resolution that orders the DOC to end solitary confinement for those who are returning to jail. The mayor said the law “promotes transparency within our city jails … and will help us to manage the jails more effectively and address the problems that were left to us.”

The DOC has been under intense pressure to reform its policies after the deaths of two mentally ill inmates were exposed in a report earlier this year by the Associated Press. One inmate died of hyperthermia in a 101-degree cell. The other inmate, who was diabetic, sexually mutilated himself while locked up alone in a cell for seven days.

At press time Wednesday, the City Council’s Committee on Juvenile Justice had an oversight hearing on the DOJ’s report and the treatment of teen inmates in New York City jails.