Father: Before NYC Bombing, Suspect Became Secretive, Changed Locks on Door

Father of Ahmad Rahami tells ABC News' Brian Ross his son acted alone.

— -- Just a few months before two explosive devices went off in New York and New Jersey, bombing suspect Ahmad Rahami became increasingly secretive around his family and went as far as changing the locks on his bedroom door to keep people out, according to Rahami's father.

"Nobody can go in," the father, Mohammad Rahami, told ABC News' Chief Investigative Correspondent Brian Ross in his first in-depth broadcast interview to be shown on "Good Morning America". "One time, my grandson, he went to his room and [Ahmad] is screaming and kicking him out. He's a little 4-year-old."

The elder Rahami maintained that no one in his family had any idea about what Ahmad was allegedly planning, and never saw him with bomb components or a gun.

TUNE IN to "Good Morning America" Wednesday at 7 a.m. EST for the full report.

FBI Director James Comey told lawmakers today that investigators have seen "no indication" that Rahami was part of some larger terrorist cell and that there is little threat of related attacks.

But Comey's officers are still desperately trying to identify and speak with two men that authorities say may have incidentally made off with a bag that had housed one of the explosives planted in Ahmad's alleged plot.

Today the FBI released more images of the two men with the bag. The men are not considered suspects.

Ahmad Rahami, 28, remains in a New Jersey hospital where he's being treated for the seven gunshot wounds he received after he allegedly engaged in a gun battle with police two days after the bombings. He has been charged with a litany of crimes related to the purported attempted bombings and the firefight.

ABC News' Shahriar Rahmanzadeh and Lee Ferran contributed to this report.