Transcript for A look at ISIS recruitment tactics in America
So many cyclists and pedestrians have returned in a sign of strength. This evening a stunning look at ISIS in America right now. Diane sawyer and the marine father discovering his own son in his own home had been lured in by ISIS. But not before it turned deadly for one of their neighbors. This is your son? Yes. Reporter: A desperate father calls 911 about his son. I need somebody as quick as possible. We have units en route to you. Stay on the line with me okay? I don't know if it's ISIS or what. Reporter: You can hear his son in the background. Why are you trying to say I'm a terrorist? Reporter: Justin Sullivan grew up as a boy in a catholic home with trophies, friends, a bedroom filled with childhood toys. His dad, a retired marine captain, rich Sullivan. I imagined him joining the military. And to follow in my footsteps. Reporter: But his high school reported to the parents that Justin had violent fantasies in his writing and suspended him. They said he needed serious help. The parents had no idea that their 18 year old son alone with his computer had reached out to ISIS recruiters. In less than 24 hours, a top captain of ISIS responded. 6,184 miles away. "Welcome brother, blessings upon you. Justin is lonely. ISIS can fix that." Then another key step, tap into the fantasy. And we know Justin loves the video game call of duty. If Justin takes violent action, they will make him a hero, a celebrity. Justin Sullivan puts on a ski mask, and murders a neighbor with his father's rifle which he hides. Police find the neighbor's body, but have no suspect. And then in a few months, he tells his ISIS recruiter, he is ready to go big. Reporter: He is going to get an assault rifle and slaughter people at a concert in north Carolina or at a club. But as the clock is ticking down, his parents happen discover a package containing a gun silencer. I called the police department, I said, "I need to talk to somebody in homeland security." Tonight a father from north Carolina has a warning for parents. Here I am defending our country against domestic enemies, which so happened to be my son. Diane sawyer investigating and this is chilling. Her one hour special ISIS in America is tonight. What authorities are following in this country right now and how ISIS is recruiting in the U.S. Tonight 10:00 P.M. Eastern. We hope you watch Diane at 10:00.
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