Court records indicate Rahami was from a large family and may have as many as seven siblings.
One of his brothers is now in Afghanistan. His mother left the country just three weeks ago and has not returned since. In a 2014 arrest, he was accused of stabbing his brother in the leg with a knife, charges that were eventually dismissed because she declined to cooperate.
A U.S. official told ABC News Rahami was born in 1988 in Afghanistan, came to the U.S. in 2000, and former classmates say he attended Edison High School in New Jersey.
He was a "pretty normal guy", quiet but funny, according to Chris Konya, one of the classmates.
It is in every way the embodiment of the American dream; an immigrant family so proud of their adopted homeland, they named their chicken restaurant "First American".
But Monday evening, federal agents removed box after box of evidence from the restaurant, as the family's own flesh and blood stands accused of an act of terror.
"He was just always a kind, funny, nice person," said Flee Jones, a childhood friend.
Friends describe Rahami as a clean-cut, all American graduate of Edison High School, a happy kid, interested in sports and girls.
"Ahmad had a girlfriend who became pregnant, who was far along in her pregnancy at the prom. And I know that she ended up, they ended up giving birth to a baby girl," said Flee Jones, a childhood friend.
After studying criminal justice at Middlesex County College from fall 2010 to fall 2012, Rahami worked in the family's restaurant, and at a restaurant in Perth Amboy, before traveling overseas.
U.S. officials told ABC News he flew to Afghanistan and Pakistan and spent nearly a year in the city of Quetta in 2013 and 2014. Later, he told authorities he had a wife in Pakistan.
A New Jersey congressman says that Rahami contacted his office from Pakistan in 2014 to help get his pregnant wife a visa.
Rep. Albio Sires said that Rahami emailed his office from Pakistan in 2014 seeking help because his wife had an expired Pakistani passport.
Sires said his office wrote a letter to the U.S. embassy in Pakistan to check on the status of the case and that the woman eventually received a visa. He says he doesn't know if she ever came to the country and the FBI didn't answer when asked on Monday.
Sires says he contacted the FBI about the encounter on Monday after Rahami was named as a person they were seeking for questioning.
Friends say Rahami returned from his visits a changed man.
"His attire was different, the way he was talking quieter," Jones said.
Rahami was captured not far from his home in Elizabeth following a shootout with police. Rahami was wounded, and two officers suffered non-life threatening injuries.
He was charged with five counts of attempted murder of a law enforcement officer. He was also charged with second-degree unlawful possession of a weapon and second-degree possession of a weapon for an unlawful purpose.
The FBI earlier released a wanted poster and New Jersey State Police released additional photos of the 28-year-old suspect in Saturday night's Chelsea bombing and the earlier explosion in Seaside Park, New Jersey.
Sources tell ABC News that authorities believe ALL of this past weekend's incidents -- explosions in Seaside Park and Chelsea explosion, the un-exploded pressure cooker on West 27th Street, and the devices found/detonated at the Elizabeth train station -- are connected.
A source says authorities were able to identify Rahami with help from a cell phone left behind with an un-exploded pressure cooker found on West 27th Street.
Rahami, a naturalized citizen of Afghan descent, is believed to be the man seen in surveillance video at both the scene of the explosion and the scene on West 27th where the unexploded device was found, according to a police source.
The blast on 23rd Street injured 29 people.
No one was injured when the pipe bomb that exploded Saturday in Seaside Park before a charity 5K race to benefit Marines and sailors. The race was canceled.
Five more devices were found in a bag in a trash can by two men at around 8:30 p.m. Sunday near the Elizabeth train station. One of the devices exploded as a bomb squad was attempting to disarm it with a robot. No one was injured.
Some information from The Associated Press and ABC News