The U.S. State Department says a 33 year old San Diego man died fighting for the Islamic State of Iraq and al-Sham (ISIS) over the weekend.  Douglas McAuthur McCain was believed to be one of three men killed in a battle Sunday according to the Free Syrian Army.

Douglas McCain grew up in Illinois and was raised as a Chrisitian, lived in Minnesota for a while before moving to San Diego where he attended San Diego City College and was known to hang out at a mosque near City Heights.

McCain's uncle, Ken McCain, told CNN that his nephew had converted from Christianity to Islam several years ago. The family wasn't alarmed by his conversion, but they became aware of Facebook posts sympathetic to ISIS, an Islamist militant group, when he traveled to what they believed to be Turkey. U.S. counterterrorism investigators had been looking into Douglas McCain for some time before his death, one U.S. official said.

He was among a list of Americans who are believed to have joined militant groups and who would be stopped and subjected to additional scrutiny if he traveled, according to the official. Whatever group he ended up with, the fact that Douglas McCain became a jihadi left his family "devastated" and "just as surprised as the country," Ken McCain said. He described the nephew he knew as "a good person, loved his family, loved his mother, loved his faith" -- the latter being a reference to the Christianity he practiced before his conversion.

McCain called himself "the slave of allah" on his Facebook page. On twitter, his name was Duale Khalid with a handle of "i am the tooth.  Among his most recent tweets were these:

"It takes a warrior to understand a warrior. pray for isis."

"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."

"Ya allah when it's my time to go have mercy on my soul have mercy on my bros."