Transcript for Attention of Investigation Shifts to Omar Mateen's Wife
The FBI right now is laser focused on the gunman's wife. ABC news has just learned that after agreeing to be questioned, authorities confronted her with closed circuit TV footage from around Orlando. And then, a polygraph. This video. This is omar Mateen's wife getting into that car, agents escorting her back to her apartment to pack up her things. It's not clear where she is tonight. But the gunman's family tells ABC news that the wife is, in fact, under FBI scrutiny, and all of this comes as we learn more about the shooter's secret life. What a former classmate is now revealing to us, and patrons of that Orlando nightclub who say he'd be there several times before. ABC's senior justice correspondent Pierre Thomas is in Florida, leading us off. Reporter: Tonight, the FBI is locked in on the wife of omar Mateen, trying to determine if she had any direct knowledge of her husband's deadly plot. Law enforcement sources say that Noor Salman allegedly went with her husband to buy ammo and a holster and, prior to the attack, had gone to the pulse nightclub with him at least once. ABC news has learned she has allegedly suggested to investigators that she tried to talk her husband out of harming anyone. But it's unclear whether she knew or believed an attack was imminent. Today, her father-in-law telling Linzie Janis that Salman was under FBI scrutiny. They spoke to her. I want to leave it that. And I don't want to talk about anything. Reporter: Salman agreed to answer questions when they showed her closed circuit television at locations in Orlando. Investigators are trying to determine if they were scouting possible targets. After she started answering questions, agents polygraphed her to determine if she was telling them the truth. Last night, Salman could be seen going back to her apartment, after the FBI search. Inside the couple's apartment, video shot by univision shows a seemingly Normal young family of three. She was super sweet. Super sweet and a fantastic mother. Reporter: Mateen at one time has been under FBI surveillance for ten months. A fact that the owner of the store that sold him the guns, a former NYPD cop, was not aware of. So, law enforcement guy. Would you have liked to have known that the FBI was investigating him for terrorism? Would have been fantastic. He wouldn't have gotten a gun. A frustrated gun store owner tonight. And Pierre Thomas joining us live. Pierre, is there a chance this wife will now be arrested? Reporter: David, there certainly is. If they determine she knew about this attack beforehand, it's likely think will charge her, because they want to send a message. If someone nopes about potential mass murder, they have to come forward. David? Pierre Thomas leading us off tonight from Florida.
This transcript has been automatically generated and may not be 100% accurate.