(Reuters) - More than 13,500 times last year, New York's state prison system isolated one of its 56,000 inmates from the general prison population and each stay in solitary confinement lasted an average of five months, according to a New York Civil Liberties Union report released on Tuesday.
The report calls the state's use of isolation and segregation of inmates "arbitrary and unjustified" and urges the adoption of clear criteria for employing confinement to punish prisoners.
"Virtually any prisoner can go to ‘the box' for breaking any prison rule," NYCLU executive director Donna Lieberman said at a Manhattan news conference.
She said in some cases isolation was ordered for "substance abuse, talking back, and - I'm not making this up - having too many postage stamps in your cell."
About 8 percent of New York state prisoners are held either in solitary confinement or in a cell with another inmate 23 hours a day. But only about 16 percent of isolation cases are due to violent behavior, according to the report, which says the average stay in isolation is five months.
There were 563 assaults on staff and 666 inmate assaults on other inmates last year, out of a population of about 56,000, according to the New York State Department of Corrections.
Reporters were invited to stand inside a seven-by-10-foot (two-by-three-meter) wooden box designed to supposedly replicate the experience of solitary confinement.
New York State Department of Corrections Commissioner Brian Fischer disputed the study's conclusions.
"As a society removes those individuals who commit crimes, so too must we remove from general population inmates who violate the Department's code of conduct and who threaten the safety and security of our facilities," it said in a statement. "The possession of drugs, cell phones and weapons pose a serious threat within this and any other prison system."
The yearlong NYCLU study - which gathered data through open records law requests and correspondence with about 100 prisoners who have spent time in isolation - is the latest in a series of reports focusing on standards for inmate isolation in U.S. prisons.
Last week, Amnesty International released a report critical of California's extensive use of solitary confinement at two state prisons.
In June, a federal lawsuit was filed on behalf of mentally ill prisoners isolated at Colorado's so-called Supermax prison in Florence, and the U.S. Senate held a hearing for the first time to examine the use of isolation in federal prisons.
At the hearing, Democratic Senator Dick Durbin of Illinois said about 56 percent of Illinois state prisoners have spent time in isolation.
The percentage of New York's inmates held in isolation is slightly higher than the number of similarly restricted federal inmates, according to the Federal Bureau of Prisons statistics.
Citing letters to the NYCLU, Lieberman said one inmate in isolation described being in "physical and emotional pain 24 hours a day." Another appeared suicidal, writing that "they're going to kill me anyway, so I might as well do it myself."
A 2007 New York state prisons report - the most recent available - found that 83 percent of New York's prison population showed a need for substance abuse treatment.
Editing by Barbara Goldberg