The man charged as the alleged New York pipe bomber, Ahmad Khan Rahami, is a 28-year-old Afghanistan-born US citizen whose parents run a fried chicken restaurant in Elizabeth, New Jersey, 24km from New York.

The New York Times has reported that Rahami was known to some friends as “Mad”, which was simply an abbreviation of his name rather than any reference to his mental state.

As well as having a penchant for racing souped-up Honda Civics, Rahami worked behind the counter at his parents’ shop where he was known among friends for giving them free food when they were short of money.

Rahami’s parents’ restaurant in Elizabeth, New Jersey. Photo: AAP.

In recent years, the paper reported that some friends had noticed a change in his personality and religious devotion after what they suspect to be a visit to his birth country of Afghanistan.

The Times reported that when Rahami returned from Afghanistan, he showed possible signs of radicalisation, with some customers noticing a change in the previously genial man.

He grew a beard and swapped T-shirts and sweatpants for traditional Muslim robes, and began to pray in the back of the store.

“It’s like he was a completely different person,” one customer reportedly said. “He got serious and completely closed off.”

And for years, he and his family had a difficult relationship with neighbours and the police because of the unsociable hours the restaurant kept, and due to its noisy customers.

Rahami was born in Afghanistan in 1988, with media reporting that he had come to the US when he was just eight years old along with at least five siblings, although others report that it was unclear when he came and the size of his family.

– with the New York Times