The parents of Claudio Neves Valente had not seen or heard from him since he left Portugal for the United States to enroll at a graduate program at Brown more than two decades ago.
Claudio Neves Valente and Nuno Loureiro, the M.I.T. professor he is accused of killing, were classmates at the University of Lisbon’s Instituto Superior Técnico from 1995 to 2000.
John Koch, a radio reporter, witnesses every execution in Florida to keep close tabs on what he considers one of the most consequential actions the state takes.