NEW YORK (WPVI) --Authorities continue to question the family of the man suspected of planting bombs in New York and New Jersey.
Now his father is sitting down with ABC News for his first, full TV interview and he's revealing surprising details about his son.
Mohammad Rahami maintains his family had nothing to do with the alleged bombings and he had no idea what his son, the suspected bomber, was planning.
In fact, he says he hasn't spoken to the suspect since they had a falling out in May.
The father of the accused terrorist, Ahmad Rahami, says he is certain his son acted alone, adding he does not know the two men, seen in surveillance pictures, sought by the FBI as witnesses.
"He did everything by himself. He buys everything by himself. He orders and online - he did it by himself," said Mohammad.
Mohammad Rahami explained to ABC's Brian Ross that his 28-year-old son had become seretive months before he allegedly planted bombs in New York and New Jersey - even changing the locks on his bedroom door in the family apartment.
"Nobody can go in. One time, my grandson, he went to his room, and he's screaming and kicking him out back. He's little - 4-years-old," said Mohammad.
But the father says no one in the family saw this coming.
"Nobody, nobody. Believe me. I guarantee," he said.
This, as federal agents tell ABC News they are now examining some of the radical social media posts shared by the suspect's older sister, whom he visited in Pakistan.
But he still never spoke of any of it to his family in New Jersey.
Mohammad said he did, however recognize one of the FBI agents present when his son was shot and captured last week, saying the same agent had investigated his son as a possible terrorist. He says the agent never interviewed his son, although he believes they should have, and concluded he was no terror threat.
According to the FBI, the agent conducted a thorough investigation even after Mohammad recanted his original statements about his son, something he now disputes.