On the morning of June 18, 1998, Jonathan Rosen received a call from his mom, warning him not to go home. An old childhood friend of his, Michael Laudor, 35, had been involved in an incident, possibly hurting his fiancée Carrie Costello. “Hurt her how?” Rosen asked his mom. In fact, writes Rosen in his new book, “The Best Minds: A Story of Friendship, Madness and the Tragedy of Good Intentions” (Penguin Press) Carrie was more than hurt. She was found in her Hastings-on-Hudson apartment in a pool of blood, with multiple stab wounds to her head, neck, and back....