As we come on the air we are learning new details about the American connection inside the deadly terror group Isis. Another American recruited by them and killed while fighting with their forces in... See More
As we come on the air we are learning new details about the American connection inside the deadly terror group Isis. Another American recruited by them and killed while fighting with their forces in Syria. So how many Americans are they and what are their goals? ABC's chief investigative correspondent Brian Ross is back on this case for us again tonight. Brian? The American citizen reported killed is precisely the sort of Isis recruit that authorities have worried would gladly sacrifice himself for his jihad I cause whether there or here. He grew up in Minnesota and went to college in San Diego. On his Facebook page, 33-year-old Douglas Mcarthur McCain hardly appeared to be a dangerous jihadists. His likes included pizza hut, the Chicago bulls and the Koran. He was reportedly killed in Syria while fighting for the brutal terror group Isis, this according to a rival militant group. In a Twitter message earlier this year, McCain who converted to Islam a decade ago, wrote stand strong, we will soon be won. I felt like he may have lost his identity because all of this is not him. Reporter: An estimated 100 Americans have been recruited to fight for jihadist groups in Syria, including Isis. I'm feeling like I'm still dreaming. I'm thinking like I'm in a dream world. Reporter: Earlier this summer the Syrian Al Qaeda group said an American from Florida carried out a suicide bomb attack for them and left behind this threatening video for fellow Americans. You think you are safe. You are not safe. Reporter: As brutal and outrageous of the killing of American journalist James Foley was, Isis is a greater threat. They may have again a place to organize a major attack on the United States. There are was no news about the fate of American journalist Steve sof love and two others including a young female aid worker. President Obama issued his own word to those responsible in Isis. America does not forget. Our reach is long. We are patient. Justice will be done. Reporter: But the president went on to say that going after and rooting out Isis won't be quick or easy. He said our reach is long. Thank you, Brian.
This transcript has been automatically generated and may not be 100% accurate.