Two years ago, Ahmad Khan Rahami's father told New Jersey police that his son was a terrorist, who then reported it to federal agents, according to a report.

In a sporadic and violent family atmosphere, the father made the statement about his son when Rahami was arrested after a domestic dispute and accused of stabbing his brother.

The information was passed to the Joint Terrorism Task Force led by the Federal Bureau of Investigation in Newark. Officers opened what is known as an assessment, the most basic of F.B.I. investigations, and interviewed the father, who then recanted.

Early Tuesday morning, the father, Mohammad Rahami, told the press, “I called the F.B.I. two years ago,” he said. A reporter asked, “Do you think your son is a terrorist?”

“No,” Mohammad Rahami said. “And the F.B.I., they know that.”