Washington — They're small spaces -- sometimes 7 feet wide, 12 feet long. And they're where some inmates are held, sometimes for days, sometimes for decades.
Religious leaders across the country are speaking out against solitary confinement cells that they say should never be used by juveniles or the mentally ill and rarely by the general prison population.
The debate is taking on new resonance as a Boston jury weighs the death penalty -- or a life sentence with 23 hours a day in solitary confinement -- for Dzhokhar Tsarnaev, the convicted Boston Marathon bomber.
From Wisconsin to Washington, activists have taken replicas of a solitary confinement cell to places where people on the outside can momentarily experience what life is like on the inside. A Buddhist chaplain, haunted by the sights and sounds of her visits to prisoners in solitary, brought one to the Wisconsin Capitol in the fall.
"Once you've stood inside the cell and heard the sounds of an actual solitary confinement unit echoing in your very being, it becomes very hard to forget or to ignore," said the Rev. Kate Edwards, a Zen Buddhist in Madison, Wis. "The reality that solitary confinement is a loud and torturous living hell simply becomes undeniable."
From the statehouse, the replica, which includes a recording of the banging and screaming from a real prison, has been featured in various churches and at Marquette University, a Catholic school in Milwaukee.
Other groups, such as the American Friends Service Committee (Quakers) and T'ruah: The Rabbinic Call for Human Rights, have taken their fight against solitary confinement to the United Nations and provided shadow reports to its Committee Against Torture. In the Quakers' report, inmates who had been in solitary described suicide attempts, lost weight and dungeon-like circumstances.
In its concluding report, the U.N. committee said that despite statements from Washington that there is "no systematic use of solitary confinement" in the U.S., at a minimum, the practice should be prohibited for juveniles and people with mental illness.
"Full isolation of 22 to 23 hours a day in super-maximum security prisons is unacceptable," the committee said in its December report.
Experts say an estimated 80,000 people are in solitary in U.S. prisons each day, with some spending years there.
Rabbi Rachel Kahn-Troster, the director of programs for the rabbis group, has journeyed with interfaith groups for visits to Rikers Island and Sing Sing, two New York facilities that include solitary confinement for some prisoners.
"When you talk about ending the death penalty, so much hinges on the question of innocence. Solitary confinement forces us to ask other questions," she said. "Whatever people may or may not have done, how do we treat them when we are trying to rehabilitate them? Why does our prison system focus on continuing to punish people rather than trying to figure out how to rehabilitate them?"
Halfway across the country from the Wisconsin cell replica, the National Religious Campaign Against Torture created a model of its own. It appeared at an Episcopal church in Washington in March and an ecumenical conference in April and is scheduled to be featured at the Baltimore convention of the Islamic Circle of North America over Memorial Day weekend.
"It's not something that should be acceptable in society," said Rameez Abid, spokesman for ICNA's Council for Social Justice. "There's just not much awareness in the community, so we wanted to bring it into the light."
He and other faith leaders who visited the cell at the Ecumenical Advocacy Days conference in April spent three minutes inside, listening to recorded sounds of life in solitary.
"I already wanted out," he said.
The Rev. Laura Markle Downton, director of U.S. prisons policy and program for NRCAT, supplies context for visitors to the cell replica. It represents the place where inmates spend 22 to 24 hours a day, often getting an hour away for "recreation" in a space that "looks like a dog run."
And the inmates who end up in solitary are often there for nonviolent infractions: "Something as simple as 'reckless eyeballing,' having one too many postage stamps, having one too many pencils," she said.
An independent assessment released by the Federal Bureau of Prisons in December found that "general conditions of confinement in restricted housing units are consistent with national regulations and standards." It noted a population decline of 31 percent in one of the bureau's three restrictive housing programs, from 13,000 in 2011 to 8,939 in June 2014.
"Restricted housing is an important tool for corrections to accomplish our mission," the Bureau of Prisons said in a February response to the assessment. "Offenders who pose a threat to the safety and security of prisons, or who require protection from other inmates, must be housed in more controlled environments."
Activists hope visitors who experience a glimpse of life inside the cell will work with clergy to lobby state legislatures to change prison rules and reduce the use of solitary confinement.
Tim Head, executive director of the conservative Faith and Freedom Coalition, said coalitions of faith leaders focused on the larger issue of mass incarceration also are beginning to discuss solitary confinement.
"It's percolating, but not front and center," said Head, whose organization, founded by political strategist Ralph Reed, recently joined forces with progressives to launch the Coalition for Public Safety.
Head, a former Texas evangelical minister and social worker, has counseled prisoners and agrees solitary confinement is used too frequently. "I don't necessarily advocate for the complete abolition of the practice, but it needs to severely be restricted," he said. "It's just a universal punishment bottom line for far too many."
That's the gist of what the retired Catholic archbishop of Galveston-Houston, Joseph Fiorenza, and Austin Rabbi Neil Blumofe said in a commentary in the Houston Chronicle last month, where they pointed out that, on average, individual Texas inmates spend close to four years in solitary.
"Many state departments of corrections, from Mississippi to Maine, have implemented humane alternatives to isolation," they wrote. "It is time for Texas to reform its use of solitary confinement."
Still other protesters of solitary confinement have taken a step into another part of the justice system: the courthouse. Lynne Iser, board member of a Reconstructionist synagogue in Philadelphia, has joined other members in attending four court hearings of the so-called Dallas 6, inmates who protested solitary confinement conditions in Pennsylvania's State Correctional Institution at Dallas.
The activists became "supporters and allies" of the inmates after their study of mass incarceration led them to meet community members, including a woman whose father was in solitary for 30 years and the mother of one of the Dallas 6.
"It just doesn't sit with my sense of justice," Iser said. "The role of prison is not to rehabilitate but to imprison and be punitive, and that doesn't serve our society."