John Steele has a characteristically thoughtful Legal Ethics Forum post about the dilemma faced by a criminal defense lawyer who is assigned as "shadow counsel" to a pro se defendant -- in this case Maj. NIdal Malik Hasan, charged with 13 counts of premeditated murder and 32 counts of attempted murder in the 2009 mass killings at Fort Hood -- when the "shadow client" plans to use a legally suspect defense. Hasan apparently is planning to use an "defense of another" defense, the "other" being the Taliban. The appointed counsel are said to believe the defense crosses an ethical line. Steele believes the shadow counsel should set aside their own views and support Hasan "even if the defense is unpalatable and likely to fail":
The defense theory Hasan likes is, apparently, that the shootings at the military base in Texas were done in defense of the Taliban. It's a "defense of third party" theory. Presumably it would be an "imperfect necessity" argument: that the acts were done in the actual but unreasonable belief that they were necessary. That is neither justification nor excuse. At best, it's mitigation. But it does give the accused the chance to speak honestly and openly about why he did what he did. That is a close analog of the defense that the Unabomber wanted to raise but was prevented from raising because the federal public defenders deceived him and then put on another defense. (William Finnegan's classic article about that case, Defending the Unabomber, is under a paywall, unfortunately.) It's a reasonably close analogy of the defense that John Brown wanted to raise. In both the Unabomber and the John Brown cases, the defense preferred to raise mental health defenses.