NEW : Source says the suspect has been considered mentally unstable . Bin al-Shibh 's lawyer , Thomas Durkin , said Tuesday that he was unaware until now that the tapes involved his client . Tapes found in 2007 show Ramzi Bin al - Shibh being questioned . Suspect 's lawyer says he did n't know the tapes existed . Bin al - Sharif is one of five terrorism suspects facing trial .
NEW : Source says the suspect has been considered mentally unstable . Tapes found in 2007 show Ramzi Bin al - Shibh being questioned . Suspect 's lawyer says he did n't know the tapes existed . Bin al - Sharif is one of five terrorism suspects facing trial .