A black SUV pulled up to Abdulrahman Sameer Noorah’s home in Southeast Portland two weeks before his June 2017 trial. Noorah, a Saudi national charged the year before in the fatal hit-and-run of a teenage girl crossing Hawthorne Boulevard, had a bag packed that Saturday afternoon. The private car drove the 21-year-old Portland Community College student to a sand-and-gravel yard two miles away. That’s where Noorah sliced off the tracking monitor he had worn around his ankle for months, according to interviews with federal authorities. He then discarded it at the scene before vanishing, leaving a victim’s family crushed and prosecutors furious and...