. >> reporter: her sister fowzia made the decision to speak to cnn from her home in karachi, pakistan, because the family doesn't want terrorists carrying out attacks in aafia's name. after the brutal beheading of james foley, a letter sent to his family reveals how isis claimed to have requested aafia siddiqui's release. it said we offered prisoner exchanges to free the muslims currently in your detention, like our sister, aafia siddiqui. >> any kind of kidnappers, isis, whoever wants to claim aafia, i am aafia's sister. we are aafia's family. and we speak on her behalf as well. we want no violence in aafia's name. our whole struggle has been one that is dignified, that is peaceful, and that is legal. >> reporter: a pakistani neuro scientist in the u.s. went missing. then she was listed as a sought after al qaeda member. in 2008, she reappeared, stopped by afghan national police, for acting suspiciously outside a government building. she was accused of shooting at two fbi agents and several military personnel, while being held at an afghan facility and sentenced by a u.s. federal jud

reporter: aafia siddiqui's sister fowzia made the decision to speak to cnn from her family home in pakistan because the family doesn't want terrorists carrying out attacks in aafia's name. after the brutal beheading of journalist james foley a letter sent to his family reveals how isis claims to have requested aafia siddiqui's release. it read "rev also offered prisoner exchanges to freet muslims currently in your detention like our sister dr. aafia siddiqui." not in our name, says her family. >> any kind of kidnappers, isis these days, the aafia brigade, or whoever wants to claim aafia. i'm afia's sister. we're aafia's family. and we speak on her behalf as well. we want no violence no aafia's name. our whole struggle has been one that is dignified, that is peaceful, and that is legal. >> reporter: a pakistani neuroscientist based in the u.s., aafia went missing in 2003. a year later she was named on the fbi alerts list as a sought-after al qaeda member. in 2008 she reappeared, stopped by afghan national police for acting suspiciously outside a government building. she was accused of shooti