An Islamic State defector who claimed in news interviews to have refused to commit violence for the group has been charged by German authorities with murder and war crimes for his role in a mass execution in Syria in 2015.

Harry Sarfo, a 28-year-old German citizen, appeared in front-page articles and television broadcasts last year in which he offered a sanitized version of his involvement with the Islamic State and condemned the group’s tactics.

But his account began to unravel after The Washington Post obtained and published a video that showed Sarfo helping to move prisoners into position for a public execution in the ancient city of Palmyra, and apparently firing his own weapon as the men fell in a barrage of machine-gun fire.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.