The men, Muslims, file quietly into a classroom of white cinderblock that serves as their mosque. Incense burns to chase away a sour smell from the hall, as the inmates sit quietly on sheets stamped ''Department of Corrections'' covering the linoleum floor.
Imam Menelik Muhammad is delivering the day's sermon. As he stands beneath a Quranic prayer on the wall facing Mecca, he urges the prisoners to reform. ''You will not be considered a Muslim,'' he admonishes, ''unless people are considered safe from your hands and your tongue.''
Across the United States, tens of thousands of Muslims are practicing their faith behind bars. Islam is most likely to win American converts there, according to U.S. Muslim leaders, and the religion has for decades been a regular part of prison culture.
But the Sept. 11, 2001, attacks have brought new scrutiny to Muslim inmates, many of whom are black men focused on surviving incarceration. While prison chaplains of various denominations argue that Islam offers a spiritual path to rehabilitation, others say it has the potential to turn felons into terrorists. The FBI calls prisons ''fertile ground for extremists.''
The reality is harder to read: Those on opposing sides have such divergent views they seem irreconcilable. Who's right matters not only for national security, but for the development of American Islam itself, which is struggling to be accepted alongside the major faiths in the United States.
Ever since the 2002 arrest of Jose Padilla, a felon and American Muslim convert who authorities say planned a ''dirty bomb'' radiological attack after he left jail, law enforcement officials, politicians and even a few evangelical leaders have warned that Muslim inmates are ripe for terrorist recruitment.
Sen. Charles Schumer, a New York Democrat, has said: ''Wahhabi influence is inculcating them with the same kind of militant ideas that drove the 9-11 hijackers to kill thousands of Americans.'' Wahhabism is a strict form of Islam practiced in Saudi Arabia, which was home to 15 of the 19 hijackers.
Chuck Colson, founder of the evangelical Prison Fellowship Ministries and a Nixon administration official, predicted that ''radical Islamists will use prisons, packed with angry and resentful men,'' to avenge Islam.
''Prisons continue to be fertile ground for extremists who exploit both a prisoner's conversion to Islam while still in prison, as well as their socio-economic status and placement in the community upon their release,'' FBI Director Robert Mueller said Feb. 16 to the U.S. Senate Intelligence Committee.
Prison chaplains and others say such warnings are dangerously ignorant.
In interviews with The Associated Press, chaplains, prison volunteers, correctional officials, inmates and former inmates all insisted that there was no evidence of terrorist recruitment by Muslims in their prisons - although banned pamphlets and books sometimes slip in.
Chaplains describe the typical inmate convert as a poor, black American upset about racism, not Mideast politics, or someone who turned to Islam to cope with imprisonment. When they get out, these men are so overwhelmed by alcoholism or poverty that the crimes they are most likely to commit are the ones that landed them in jail to begin with, chaplains say.
''They don't care about Osama bin Laden,'' said Imam Talib Abdur Rashid, who worked for years as a chaplain in New York state's prison system. ''They have their own beefs that have nothing to do with shariah [Islamic law], the Taliban or Wahhabism, and everything to do with slavery, segregation and the history of U.S. racism.''
Just defining the scope of the Islamic presence behind bars in the United States is tricky.
Though on the federal level they account for about 6 percent of roughly 150,000 inmates, there are no nationwide statistics on Muslims in state prisons.
Experts believe the largest numbers in state prisons can be found in New York, where Muslims are roughly 18 percent of the 63,700 inmates; Pennsylvania, where the figure is about 18 percent out of 41,100; and California, where state officials don't tally religious affiliation but the figure could easily be in the thousands.
The bottom line is that the percentage of American Muslims in prison is almost certainly higher than it is in the general population, where the number of Muslims could be as high as 6 million, or roughly 2 percent.
Islam took hold in prison in the 1940s, through the Nation of Islam. Leaders of the religious movement, which mixes Muslim traditions with black nationalism, were imprisoned for refusing to fight in World War II and, as a result, their teaching spread behind bars. Among their most famous prison recruits was Malcolm X.
Another boom came two decades later, when Muslim inmates sued prison administrators, accusing them of violating religious freedoms. The inmates won, and transformed jailhouse practice of all faiths.
Starting in the 1980s, get-tough sentencing laws filled jails with a disproportionate number of blacks, leading to another spike in conversion. But by this time, many blacks who once belonged to the Nation of Islam had embraced orthodox Islam instead - and that is what the majority of inmates practice today.
Or, at least they say they do.
Some inmates become Muslim in name only, either to seek protection from prison gangs, enjoy privileges like holiday meals, or escape the monotony of prison life through classes and weekly worship. Mika'il DeVeaux, a Muslim convert who spent 25 years in New York prisons for murder, encountered inmates who converted but had little or no understanding of the religion. One inmate, he recalled, thought converting would allow him to circumvent prison rules and wear a hat that looked like a turban.
But for some prisoners, the change is authentic, and correctional officials say Islamic observance actually helps them maintain prison security.
Said Anthony Windle, who converted to Islam at Rikers Island while awaiting trial on a drug conspiracy charge: ''The more you learn, the harder it is for somebody to feed you untruths and lead you in the wrong direction.''
Duval Rafq, who was convicted of rape and became Muslim two years into his Connecticut prison sentence, said converting led him to accept responsibility for his crime. Released five years ago, he worships at Masjid Al-Islam in New Haven, and works while attending night school for heating and refrigeration repair.
''My behavior all of a sudden changed and other people's attitude and behavior toward me changed,'' Rafq said.