An Iranian nuclear scientist claimed Thursday that he suffered extreme mental and physical torture at the hands of U.S. interrogators after disappearing last year, adding to Tehran's allegations he was abducted by American agents. The U.S. says he was a willing defector who changed his mind and decided to board a plane home from Washington. Shahram Amiri was embraced by his family including his tearful 7-year-old son after arriving in Tehran in the latest spectacle of a puzzling series of events that left Iran and Washington with starkly different accounts. Amiri flashed a V-for-victory sign as he stepped into the terminal.