It's a security precaution that comes with a price. For Mustafa Kamel Mustafa, it means being left for hours helpless with tasks others take for granted, such as dressing or eating. For taxpayers, it means paying more than $15,000 to outfit Mustafa with a new set of prosthetic arms with rounded fingers that can't be used as weapons.
Jeremy Schneider, the lawyer who represented Mustafa when he pleaded not guilty to the charges this past week, complained outside court that the daily removal of his client's arms is a problem.
"He has use of them for a certain part of the day but not long enough to allow him to function the way he should function," Schneider said. "As you can well imagine, he's not happy he's in a situation like this."
It's unclear how Mustafa copes during the times he's without his fake limbs. He has appeared in court handless and helpless, the rounded ends of his arms - both cut off shortly after the elbows - in plain sight.
Safety is the top priority, officials at the Metropolitan Correctional Center say. One terrorism defendant being held in the lower Manhattan lockup used a sharpened comb to poke out a guard's eye in an ill-fated escape attempt in 2000.
Authorities cite reports of people inside prisons - and outside - using prosthetics in vicious attacks. In January, an inmate in an upstate New York prison accused a fellow prisoner of assaulting him with a prosthetic arm, later telling guards it felt like being hit with a steel baseball bat. And in June, an Arkansas man was accused of using a fake arm and a rock to beat another man to death.
Traci Billingsley, a U.S. Bureau of Prisons spokeswoman, said she could not provide specific information about individual inmates but "if an inmate arrives at any of our facilities with a prosthetic that we believe could pose a danger, it would not be permitted inside."
Similarly, the U.S. Marshals Service, which transports Mustafa to and from court, does not allow him to wear the hook while in their custody.
Billingsley said inmates with prosthetics are medically evaluated to determine whether other accommodations or devices would be appropriate. Mustafa is expected to be outfitted with a new prosthetic in the shape of a hand to replace his hook hand at taxpayers' expense.
Such modern prosthetic hands can range in price from $15,000 to $100,000, said John N. Billock, head of the Orthotics & Prosthetics Rehabilitation Engineering Centre in Warren, Ohio.
Forty years ago, hooks were considered superior to prosthetics in the shape of hands, but that has changed with advances made in electrically powered prosthetic hands, he said.
"In my profession, there was a time when the mechanical hands were just considered not to be as functional. We live in a world made for hands," he said.
Billock said he has not worked with prisoners but can understand why Mustafa misses his hook. He said people missing both hands sometimes prefer to have one hook prosthetic and one hand-shaped prosthetic because they serve different purposes. Farmers, for example, like to have a hook because they can use it as a tool.
Mustafa, who fought the Soviets in Afghanistan in the 1980s, lost his arms to explosives.
Associated Press writers Gregory Katz in London and Tom Hays in New York contributed to this report.