More than one year after Layleen Polanco died of epileptic seizures after jail staff failed to frequently check on her in solitary confinement, Mayor Bill de Blasio announced he'll form a working group to end the practice.

"Layleen Polanco should not have been in solitary confinement," de Blasio said during a press briefing Monday morning.

Polanco, the 27-year-old transgender woman held on $500 bail, died on the ninth day she was in a restrictive housing unit—where she was held in solitary as a punitive measure.

De Blasio said beginning immediately, the list of medical conditions that would exempt inmates from restrictive housing or solitary confinement was expanded to include heart disease, lung disease, seizures, diabetes, among other conditions.

The Dept. of Corrections (DOC) has already ended the use of punitive segregation for people with severe mental health conditions, which Polanco was facing in the weeks leading up to her death, and people under 22-years-old.

A four-person working group will determine a way to end solitary confinement altogether in a report this fall.

"This group will have a simple mission, a simple mandate—find a way to end solitary confinement and tell us all the things it's going to take, because it will take other measures and new approaches and innovations to keep everyone safe," de Blasio said at the press briefing.

A lawyer for Polanco's family said in a statement they welcomed the news, but noted "there is still a long way to go."

"Layleen’s family is grateful to her many supporters, especially the New York City Anti-Violence Project, who have worked tirelessly to force much-needed change," her family said. "Make no mistake; the work is far from over.  To her family, Justice for Layleen means ending solitary confinement, decriminalizing 'walking while trans,' advancing bail reform, and holding Layleen’s killers, including the City itself, accountable."

"The family and the community will continue the struggle," they added.

The working group will be led by Board Vice-Chair Stanley Richards, Department of Correction Commissioner Cynthia Brann, and Just Leadership USA President DeAnna Hoskins. The Corrections Officer Benevolent Association president Benny Boscio has been asked to join.

"Previous versions of the various task forces and workin groups that were happening at the Board of Correction ... was trying to bring people along with why we need to close and end solitary confinement," Richards said in a phone interview.

Now, "we don't have to have a conversation of should we end solitary confinement, and whether solitary confinement is good or bad. We're starting from a place saying solitary confinement must end," he said.

Richards, who spent time incarcerated in solitary himself, called it a "sea shift" for the City of New York.

"We are not talking about 'limiting' or 'modifying,' we are talking about 'ending,'" he said.

The #HALTsolitary Campaign said time has "long passed" for working groups.

"Decades of research show that solitary is ineffective, dangerous, and, too often, deadly," the campaign said in a statement. "The Mayor has the power to eliminate this torture immediately and the community provided him with a detailed plan for doing so last October. The Mayor should have announced today that the Board of Correction—which has purportedly been working on rules to restrict solitary confinement for three years—would be voting on proposed rules in line with the community plan to fully eliminate solitary at its upcoming July 14th meeting."

Richards said that October blueprint would be reviewed and acknowledged the timeline could always be quicker for people currently suffering in jail—where poor conditions have been exacerbated during the COVID-19 pandemic.

A recent report found jail staffers failed to check on Polanco frequently enough the day of her death June 7th, 2019. A psychiatrist determined she shouldn't be placed in solitary—only to be overruled by another doctor six days later. She spent her last weeks of life in a psychiatric unit in a hospital while in custody, returned to Rikers Island, and was reported by officers to have refused breakfast, talked to herself, and was randomly crying and shouting.

"The medical conditions that make solitary confinement exceptionally dangerous were known long before Layleen Polanco’s death, and she might still be with her family and chosen family today had the City acted on that knowledge earlier," the Legal Aid Society said in a statement.

The Bronx District Attorney recently determined no one committed a crime in her death. The de Blasio administration announced last week 17 Department of Correction officers have been disciplined and four suspended without pay.

Changes to solitary rules at the Board of Correction had come to a standstill until Monday. The Legal Aid Society said de Blasio's announcement "appears to dead-end" the BOC's years of reform work.

"The City should end solitary confinement under any name today, and the Board of Correction should promulgate rules at once that address all forms of isolated confinement," The Legal Aid Society said in a statement.

#HALTsolitary noted: "Layleen Polanco died in solitary over one year ago. Kalief Browder died because of solitary confinement over five years ago. Bradley Ballard died in solitary confinement nearly seven years ago. Jason Echeverria died in solitary confinement nearly eight years ago. Carina Montes died in solitary over 17 years ago. Eliminate this practice now."