The administration of President Barack Obama dropped earlier military-commission charges against them when it decided in 2009 to try them in federal court in New York. But Congress blocked the civilian trials amid opposition to bringing the defendants to U.S. soil, especially to a courthouse located blocks from the trade center site.
Mohammed and the others could get the death penalty if convicted in the attacks that sent hijacked airliners slamming into the World Trade Center, the Pentagon and a field in Pennsylvania. The trial is probably at least a year away.
But New York police Detective Marc Nell said the viewing at Fort Hamilton more than a decade after 14 men in his unit were killed brought a sense of satisfaction, "a great feeling."
"It was a feeling of pride, being proud knowing that those guys were (being) brought to justice," he said.
Associated Press writers Meghan Barr and Karen Matthews in New York, David Dishneau in Hagerstown, Md., and Jessica Gresko in Fort Meade, Md., contributed to this report.