The man convicted of trying to kill Salman Rushdie spent years researching the writer’s whereabouts before stabbing him on a lecture stage, federal prosecutors said Wednesday at the opening of his federal terrorism trial.It is a second trial for Hadi Matar, who was found guilty in a New York state attempted murder case last year. The federal terror charges focus more on Matar’s alleged motive for the attack on the renowned author and free-speech advocate in 2022.Prosecutors started working on...