Transcript for Family Breaks Silence to Remember Steven Sotloff
We begin with the hunt for those Isis militants including the American who is helping mastermind their social media campaign spreading the message of fear around the world and Brian Ross has the latest on that. Good morning. Brian. Remaining hostages held by Isis including -- as U.S. Officials make their plans today satellites and spy planes are overhead in Syria looking for clues in the city of raqqah, the Isis command center. We will follow them to the Gates of hell until they are brought to justice. Because hell is where they will reside. Reporter: The Isis commander Abu Bakr Al baghdadi and his key deputies are prime targets for the U.S. And so is the hooded british speaker seen in the hostage videos. I'm back, Obama. Reporter: In the search for clues some of the recent gruesome Isis videos offer unintended leads. Here the camera pans and briefly catches a glimpse of one of the Isis camera operators and then another Isis fighter driving the truck, part of the all-important propaganda team that records and distributes the brutal videos. It's important to understand that for Isis, every act of violence only makes sense if it's also communicated. Reporter: This morning U.S. Officials tell ABC news that one of the key Isis social media architects is a one-time American college student from Boston. Abousamra on the FBI's most wanted terrorist list. For the friends and family of Steven sotloff, today will be another day to grieve but also send out the message that it is time to stand up to the terrorists who killed him. We will not allow our enemies to hold us hostage with the sole weapons they possess, fear. Reporter: We also learned about the secret that sotloff and his family managed to keep from his Isis captor, the fact that he was also an Israeli citizen, something that obviously would not have set well with these islamic extreme I haves who sees Jew, Christians and some muslims as their sworn enemies. He practiced his religion in secret. Thank you very much.
This transcript has been automatically generated and may not be 100% accurate.