Claudio Neves Valente, the suspect in the Brown and MIT shootings, had flashes of temper; former classmates describe him as confrontational and socially awkward Twenty-five years ago, two promising physicists graduated from a prestigious science university in Lisbon. On Monday, one gunned the other down at his home outside Boston after firing on a classroom of Brown University undergrads, authorities say. Claudio Neves Valente, the suspected shooter, once had a bright future. He graduated at the top of his college class, ahead of classmate Nuno Loureiro. But by the time Neves Valente confronted Loureiro at his Brookline, Mass., apartment building...