NEW YORK (NBC News) — Investigators are still gathering evidence against accused bomber Ahmad Kahn Rahami.

On Tuesday it was revealed his father, Mohammad, angrily called his son a “terrorist” two years ago after Ahmad apparently stabbed a sibling in the leg during a fight at home.

The FBI investigated the incident and Rahami’s father told investigators he made the comment out of spite.The agents found no evidence of a terrorism connection and closed the case.

Sources also say a notebook Rahami was carrying during a shootout with police included writings described by investigators as “rambling” and “disconnected” with references to the Boston Marathon bombing, Fort Hood attack and the teachings of former Al Qaeda propagandist Anwar al-Awlaki.

Investigators  are trying to figure out if Rahami was radicalized on trips to Afghanistan and Pakistan. Rahami visited his homeland of Afghanistan in April of 2013 and still has a brother who lives there, according to senior U.S. intelligence officials.