How Shahzad became a radical

People who knew them, both in Connecticut and in Pakistan, said he had changed in the past year or so, becoming more reserved and more religious as he faced what someone who knows the family well called “their financial troubles.”

Last year, one Pakistani friend said, he even asked his father, Bahar ul-Haq, a retired high-ranking air force pilot in Pakistan, for permission to fight in Afghanistan.

Mr. Haq, now in his 70s, adamantly refused, according to a person familiar with the conversation, saying that he disapproved of the mission and reminding his son that Islam does not permit a man to abandon his wife or children…

“The recession had taken a toll on them, I guess,” [a friend] wrote in an e-mail message from Pakistan. He said that their money worries became apparent in 2008 or 2009 and that Mr. Shahzad “lost his way during the financial problems.” JPMorgan Chase has since moved to foreclose on the Shelton house, which the couple had abandoned in a hurry, leaving behind clothes and toys…

“His personality had changed — he had become more introverted,” Dr. Anwar said the classmate told him. “He had a stronger religious identity, where he felt more strongly and more opinionated about things.” Dr. Anwar said he had asked the classmate whether this change had come through association with a group, and the friend said it seemed to be “on his own that he was learning all these things.”