Fifteen years after the worst terrorist attacks in American history, five of the men accused of planning the assault still haven’t faced trial, conviction or execution. They’re supposed to be judged by a military tribunal at Guantanamo Bay, Cuba. But four years after they were arraigned, that trial hasn’t even begun.

Many of the soldiers who now guard Khalid Sheikh Mohammed, Ramzi bin al-Shibh, Abd al Aziz Ali, Walid bin Attash and Mustafa Ahmed al-Hawsawi at Gitmo are too young to remember when the planes slammed into the World Trade Center.

If the accused 9/11 plotters had been tried in federal court, they “would be on death row as we speak,” Attorney General Eric Holder said in 2013.

We decided to test that theory. HuffPost analyzed the length of time between crime and capture, capture and trial, trial and sentencing, and, where applicable, sentencing and execution for more than two dozen prominent alleged terrorists captured by the U.S. government over the past two decades. We didn’t aim to be comprehensive, but we gathered a significant sample of major cases.