By Richard Winton, Hannah Fry, Salvador Hernandez and Clara Harter, Los Angeles Times SAN DIEGO - The two gunmen who opened fire at a San Diego mosque on Monday, killing three people, had met online, where they were radicalized and left behind a hate-filled manifesto, authorities revealed Tuesday. According to a witness, the pair were "fully armored" and rushed toward the entrance with handguns and rifles before a security guard shot at and struck one of them.