Last week, NY1 had an exclusive report on a new procedure on Rikers Island to keep young adults chained to desks. Now, the city's correction commissioner is defending the practice. NY1's Courtney Gross filed the following report.

The city's Department of Correction says the only way to control some of the alleged most violent inmates on Rikers Island is to chain them to a desk for hours. 

"Inmates are in restraints while they are at a restraint desk in level 1 because of safety concerns for staff and other inmates," said Correction Commissioner Joseph Ponte. "They typically are very violent. They have either slashed or seriously assaulted others."

Ponte is defending the use of restraint desks, now used instead of throwing young adults in solitary confinement. 

Just days after NY1 reported on this story and the city's Board of Correction raised concerns about the practice, the correction commissioner was taking questions at City Hall on violence at the city's jail complex, including questions about the desks. 

These inmates spend 17 hours in their cells. The rest, they are most likely chained by the ankle.

The department says they still get an hour of recreation time and are not chained in the shower. 

After NY1's story, the mayor backed the desks' use. Correction officials say these inmates are also offered educational programs while chained.

"So the focus has been on engaging them in programs, education and other things," said Jeff Thamkittikasem of the Department of Correction. "One of the ways to do that safely is to kind of provide that education and programing at desks where they aren't allowed to potentially attack other inmates or other officers," 

These new units are not the only way the city is trying to combat violence on Rikers Island. They are going after weapons.

The department sent us photos of weapons recovered last spring. The number of weapons found or confiscated on Rikers related to visits increased 538 percent between 2015 and 2016. 

Despite that number, violence persists. Stabbing were up last year by 18 percent.