Mohamed Osman Mohamud, who allegedly planned to bomb a downtown Portland, Ore. Christmas-tree lighting ceremony, seemed to be a regular American teenager, who liked sports, girls, and the night life at Oregon State University, where he studied engineering. But in the last few months, people around him say he changed: his parents were having marital issues and had recently separated, he dropped out of school, and he stopped attending mosque. “He seemed to be in a state of confusion,” said Yosof Wanly, the imam at the Salman Al-Farisi Islamic Center in Corvallis, which Mohamud attended while at college. “He would say things that weren’t true. ‘I’m going to go get married,’ for example. But he wasn’t getting married.” Mohamud is scheduled to appear in federal court on Monday on a charge of attempted use of a weapon of mass destruction. “When you think of someone doing what he did, you think of some crazy kind of guy,” said a fellow Oregon State student who knew Mohamud. “He wasn’t like that. He was just like everybody else.” Meanwhile, the mosque where Mahamud worshipped has said it did not have a hand in his radicalization and has emphasized that this incident is isolated, and Muslims in Oregon are worried they will face a backlash because of Mohamud’s alleged actions.