Young NYC Couple Arrested for Alleged Explosion Possession

Now, we go to th startling arrest of a young, manhattan couple for alleged possession of weapons and explosives popular with terrorists. She was nine months pregnant and gave birth to a baby girl in... See More

Now, we go to th startling arrest of a young, manhattan couple for alleged possession of weapons and explosives popular with terrorists. She was nine months pregnant and gave birth to a baby girl in custody. Abc's john muller has more on the strange story. Reporter: She is from a prominent family on new york's ritzy upper east side. He is a harvard graduate. But this morning, police are investigating why 31-year-old aaron green and his girlfriend, 27-year-old morgan, had an arsenal of weapons, capable of massive destruction in their greenwich village, apartment. They had a terrorists encyclopedia. They had improvised and modified firearms. A do-it-ourself sub machine gun. Reporter: Police had been investigating him for credit card fraud when they received a tip from a couple they invited into the apartment. When police went to investigate, a shocking discovery. Seven grams of a chemical called hmtb, a powerful explosive used in bombmaking. So unstable and dangerous, the entire building had to be evacuated saturday. Police also seized a flare launcher, a sawed-off shotgun with dozens of shells, nine rifle magazines and various how-to manuals on building bombs and booby traps. My best professional guess is that, they are just two very drug-addicted, delusional people that got into this sort of way of thinking of, it's sort of us against the world. Reporter: So far, potential targets or a motive have not been determined. And police say the couple have no known links to any terrorist organizations. We spoke to aaron green's lawyer. He has enter a plea of not guilty. Morgan hasy et to be arraigned because she's in the hospital after having a baby girl while in custody. We are unable to reach anyone for common on this. Police say the couple admits to being heroin users. A lot of questions here. Returning to josh. Much happier story.