When Umar Farouk Abdulmutallab takes his seat in a Detroit federal courtroom next month, he will do so as one of the most hated men in Amnerica.
But what about the woman next to him? Chief Public Defender Miriam Siefer hasn't yet spoken about her newest client, but those who came before her say representing terrorists comes with a unique set of stresses that can take a punishing toll.
"It was a huge strain," Gerald Zerkin, attorney for Zacarias Moussaoui, the only 9/11 conspirator yet to go on trial, told ABCNews.com. "I wouldn't want to do it again."
Defending a national pariah involves enormous legal pressures, a white hot spotlight, even having unnerving access to classified information that you can't share with anybody.
Zerkin, 60, only hinted at the toll he endured while assigned to defend Moussaoui, who was convicted in 2006.
"It took a physical toll," he said, though he declined to answer whether he needed to seek medical treatment.
"If they offered me KSM now, I would say, 'been there, done that,'" he said, referring to 9/11 mastermind Khalid Sheikh Mohammed.
The terrorists and the cause they represent, however, seemingly bring about the least of the headaches for the attorneys accustomed to defending the worst of the worst.
"Our job, what we do every day, is to represent people who are hated," Zerkin said. "You don't do this work very long or very well if you've got any compunction about that."
Zerkin was working as an assistant public defender for the Eastern District of Virginia Office of the Federal Public Defender when he was tapped to work on Moussaoui's defense in late 2001. It was an assignment, he said, that came as no surprise.
"After 9/11, before our office opened, I was walking down the street and ran into the chief death penalty prosecutor in the U.S. attorney's office and we both commented that if anybody in a conspiracy for this survived, it could be coming our way," he said. "Both for him and for me."
Though Zerkin said he now looks back on the experience "through the lenses of PTSD, I think," he remembered being ready for the challenge.
"I think I was excited by it. That's true," he said. "Obviously, we knew it was going to be a huge challenge."
But in the heat of a post-9/11 world where everyone was eager to lay blame for the attacks that had rocked the country's sense of stability, mounting a defense for the man who was, at the time, the sole surviving face of the attacks proved daunting.
"It is enourmously stressful -- enormously. You're under a microscope," Zerkin said. "The condition under which you work -- we have classified information. It's a strain."
Likewise, it was the attention outside the courtroom rather than the testimony inside that proved the biggest obstacle for Tamar Birckhead, one of the federal defenders for al Qaeda shoe bomber Richard Reid.
Five months pregnant when she was tapped to defend the man who tried to bring down a Miami-bound airplane with a bomb hidden in the sole of his sneaker, Birckhead said it was the public attention, not the nature of her client's crime, that got to her.
"I was definitely apprehensive just about the press coverage, really, knowing there was going to be a tremendous amount of attention to the case," she said. "And I had not been in that position."