Douglas McAuthur McCain, 33, was found with a U.S. passport, and members of his family confirmed it was him. He had been calling himself "Duale ThaslaveofAllah.''
McCain was born in Chicago, grew up in Minnesota and studied at San Diego City College, according to his Facebook page. The San Diego Community College District was checking its records in attempt to verify that.
While in Minnesota, he had been arrested at least six times on suspicion of various offenses including theft by swindle, disorderly conduct and giving an officer false information, CNN reported. A family member told the national news outlet that McCain had converted from Christianity to Islam.
McCain headed to Turkey and then traveled to Syria, according to media reports. He was subsequently placed on a potential terrorist watch list designed to generate heightened scrutiny if he attempted to board a flight heading to the U.S., according to the New York Times.
Last month, Attorney General Eric Holder said of the some 23,000 extremists operating in Syria that more than 7,000 were believed to be foreign fighters, including dozens of Americans. There they can join forces with extremist groups and "then seek to return to their home countries with training in how to carry out violence on a large scale,'' according to a U.S. Justice Department statement.
"In the face of a threat so grave, we cannot afford to be passive,'' Holder said. "Rather, we need the benefit of investigative and prosecutorial tools that allow us to be preemptive in our approach to confronting this problem. If we wait for our nations' citizens to travel to Syria or Iraq, to become radicalized, and to return home, it may be too late to adequately protect our national security.''
McCain was one of more than 100 Americans who are believed to have traveled to Syria to fight for Islamic Groups, which are known for using social media and other websites to recruit foreigners, U-T San Diego reported.
McCain is believed to have been the first American killed while fighting with ISIS, short for the Islamic State in Iraq and Syria, which is seeking to establish a government based on Shariah law. A 22-year-old Florida man, Moner Mohammad Abu-Salha, died in a suicide bombing conducted in coordination with al- Nusra Front in northern Syria, CNN reported.
An ISIS fighter with a British accent cut off the head of American journalist James Foley last week.