Federal authorities had launched an assessment of the suspect, but concluded he was not a threat two years ago. The weekend bombings are being investigated as "an act of terror," said the US attorney general.
Mohammed Rahami (3-L), the father of Ahmad Khan Rahami who is the suspect behind a September 17 explosion in New York City and a second bombing in New Jersey, talks with FBI investigators at the family's business.
Two years ago, the father of New York-area bombing suspect Ahmad Khan Rahami contacted the US Federal Bureau of Investigation (FBI) after he was arrested in 2014 for stabbing his brother in the leg, law enforcement officials told local media.
The elder Mohammed Rahami told federal agents that his son was a terrorist, but later rescinded his comment, saying he meant that he was hanging out with the wrong crowd.
The comment comes after police arrested the 28-year-old Afghan-born American on Monday following a firefight that wounded two officers in New Jersey.
Rahami has been charged with five counts of attempted murder of police officers during the shootout that led to his arrest. However, federal authorities are weighing charges over the bombings.
"The investigation is active and ongoing, and it is being investigated as an act of terror," said US Attorney General Loretta Lynch. Rahami is held on $5.2 million (4.65 million euros) bail.
US authorities suspect Rahami's involvement in a bomb blast that injured 29 people in New York City's crowded Chelsea district on Saturday. Police believe he was also behind several bombs planted in New Jersey, including one near a US Marines charity run in Seaside Park.
'A danger to himself or others'
In 2014, police arrested Rahami for stabbing his brother in the leg and illegal possession of a firearm.
However, a grand jury decided not to indict him, despite repeated warnings from the arresting officer that he was likely "danger to himself or others."
While the FBI launched an assessment of Rahami, they concluded that he did not possess extremist leanings that may lead to terrorist activities, saying he posed no threat.
"He's OK, he's clean, he's not a terrorist," Rahami's father told American newspaper "The New York Times," referring to the FBI's outcome two years ago. "Now they say he is a terrorist. I say OK."
ls/jil (Reuters, AP)