A 33-year-old American man was killed fighting alongside militants with the Islamic State (formerly known as ISIS/ISIL), NBC News reports.
Douglas McAuthur McCain, whose last known residence was in San Diego, California, was reportedly killed in a battle between two Syrian opposition groups.
A woman who identified herself as McCain's aunt told NBC News that he had "passed." A representative of the Free Syrian Army confirmed the man's death to NBC journalists, who were shown pictures of his passport and body. Senior administration officials told NBC News they were aware that McCain had been killed in Syria, adding that they believe dozens of Americans have gone there to fight with extremist groups - including, but not limited to, ISIS.
"The threat we are most concerned about to the homeland is that of fighters like this returning to the U.S. and committing acts of terrorism," a senior administration official told NBC News.
McCain -- who went by the name "Duale ThaslaveofAllah" on Facebook and "Duale Khalid" on Twitter -- was active on social media through Aug. 19 and appeared to be an aspiring rapper, who liked basketball, Rick Ross and Islam.
He was, it appears, one of about a dozen Americans who have joined the militants in their fight to establish a caliphate.
McCain said in a tweet earlier this summer that he converted to Islam 10 years ago, calling it "the best thing that ever happen to me."
I reverted to Islam 10 years ago and I must say In sha Allah I will never look back the best thing that ever happen to me— Duale Khalid (@iamthetooth) May 15, 2014
He also tweeted, in June: "It's funny to me how all these so call Muslim claim that they love Allah but always curse the one who try to implement his laws."
It's funny to me how all these so call Muslim claim that they love Allah but always curse the one who try to implement his laws— Duale Khalid (@iamthetooth) June 8, 2014
Among his listed places of work and education are "Dawah - Calling to Allah" and "Allah/God."
The man "was a good guy who loved his family and friends," a classmate told NBC News. "He would be the light in anyone's darkness. He always made you smile with his goofy self."