Militants claim to have beheaded American hostage Peter Kassig in a video published to the Internet on Sunday, purportedly from terror group ISIS. He did aid work in Syria, where he was captured. He was held hostage for over a year.
The video shows the aftermath of a beheading, in which the victim is not clearly recognizable. CNN has not been able to confirm the authenticity of the video nor the identity of the victim.
Kassig, 26, who converted to Islam in captivity, also went by the name Abdul-Rahman Kassig.
He went to the Middle East as a U.S. soldier and returned as a medical worker, feeling compelled to help victims of war.