Parents break silence on son being held by IS

The parents of a US aid worker threatened with beheading by the Islamic State group say they have broken their silence about their son’s year-long captivity because "the dynamics have changed" and they fear for his life.

Paula and Ed Kassig said they have been doing all they can to free Abdul-Rahman Kassig, 26, since he was captured in Syria more than a year ago. That includes appealing directly to his captors via YouTube and Twitter messages.

A militant threatened Kassig’s beheading in an October 3 video, in retaliation for US bombing attacks. The couple told CBS This Morning that the militants haveissued demands that are beyond their power to meet.