Legislation to change how solitary confinement is used in New York's prisons could still pass in the coming days, state lawmakers said Tuesday, while Gov. Andrew Cuomo threw cold water on the proposal because of what his office has said it would cost.

But the bill's sponsor in the State Senate said he disagrees with Cuomo's analysis, which he argued didn't account for other parts of the bill that could reduce the fiscal impact.

Cuomo said during a radio interview Tuesday morning that his office has estimated the cost of the current proposal to be more than $350 million for the state and approximately $1 billion total for municipalities.

That's because the bill would cap the number of days individuals could spend in solitary confinement at 15 days, after which they would be transferred to what the legislation calls a residential rehabilitation unit. Those would be separate units used for the therapy, treatment, or other rehabilitative programming for those that remain isolated from other prisoners.

Cuomo said he supports the bill's cap on time spent in solitary confinement and other safeguards included in the bill for certain inmates, like pregnant women, but is opposed to any legislation that would require the construction of new jails.

“I'm in favor of better, safer, more humane procedures,” Cuomo said. “What the current proposal does, however, is it mandates that the state and local jails build a new type of jail.”

State Sen. Luis Sepulveda, D-Bronx, sponsors the bill in the Senate and said Tuesday that he estimated the cost to be lower than what Cuomo projected. He argued that, because the bill would further restrict what offenses would land someone in solitary confinement, less people would be subject to the punishment overall.

“I believe we have a fundamental difference with his numbers,” Sepulveda said. “I don't believe it's the number he's saying because if you take into account the fact that we have less people in solitary confinement, costs are going to go down.”

The legislation, as it's currently written, would dramatically reduce the number of people who spend time in solitary confinement, Sepulveda said. But he's open to negotiating the legislation until he can come to an agreement on the measure with Cuomo and the Assembly.

Cuomo suggested Tuesday that the bill could be split to allow changes to the state's laws on solitary confinement without the potential for any new construction. Sepulveda didn't shut the door on that idea when asked about the possibility. He also noted that the 15-day cap in the bill is in line with what experts from the United Nations have recommended.

“Nothing is off the table,” Sepulveda said. “We have to recognize and continue to recognize that the United Nations has said that solitary confinement for more than 15 days is torture. That's the driving force.”

Assembly Speaker Carl Heastie, D-Bronx, confirmed they were still negotiating the issue, and said an agreement was still possible before they're expected to close out the session later this week.

“We're in three-way discussions on solitary confinement and I hope we can get to a place where all parties are happy,” Heastie said.

Advocates for the legislation blasted Cuomo's comments in a statement released later Tuesday. They argued that state and local facilities already have the space to create the proposed units, meaning that no new construction would be required. They were at the state Capitol lobbying on the bill Wednesday, which was also the sixth day of their hunger strike over the measure.

“HALT would not require any new prisons or jails,” the #HALTsolitary Campaign said in a statement. “The alternative units that the Governor is referencing in his statement would be limited to a small population of people who could be housed in existing facilities, but with a greater amount of time out-of-cell, meaningful programs, and interaction with other people.”

Cuomo first brought up the cost of the measure in a radio interview Monday, but stressed that he supported the idea of reforming solitary confinement, just without the major price tag that his office has concluded would come with it. He called the cost another “unfunded mandate” on localities Tuesday.

“It would say to the local county jail, you have to have not just the general population, and single cells, you now have to create a new type of jail, which is this residential rehabilitation unit,” Cuomo said.

The New York State Association of Counties came out strong against the legislation in a statement Tuesday afternoon. The group said that, whatever the final cost of the bill turns out to be, it would require local funding. That would likely be paid for through property taxes, said Albany County Executive Daniel McCoy, a Democrat.

“This particular proposal, while noble in its intent and, while addressing many issues of real concern regarding solitary confinement, would require the creation of new alternate facilities for inmates, which could cost tens of millions of dollars for each county to implement,” said McCoy, who's also president of the New York State County Executives Association. “Without a dedicated funding stream included in this bill, my fear is that the costs would only be passed onto the property taxpayers of New York.”

The state's correctional officers have their own problems with the legislation. The New York State Correctional Officers and Police Benevolent Association, better known as NYSCOPBA, said the legislation would compromise the safety of its members and other inmates outside solitary confinement.

“Designed with safety for all in mind, special housing units separate dangerous individuals from the general population, and only when they commit serious infractions,” said NYSCOPBA President Michael Powers. “They also provide safety to incarcerated individuals who would be subject to dangerous situations among the general population.”

The bill has managed to gain 34 sponsors in the Senate and 79 in the Assembly, more than half the membership of both chambers. It has yet to come to the floor in either house for a vote, despite majority support among lawmakers.

This year's legislative session is scheduled to end Wednesday, though lawmakers have said in recent days that it's likely to extend later in the week.

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