What led to the crash of Ukrainian International Airlines Flight 752 in Iran early Wednesday remains a mystery. But US officials now say the plane may have been mistakenly shot down by an Iranian missile. And, scholars disagree on whether the killing of top Iranian commander Qasem Soleimani was legal. But critics argue the Trump administration has failed to make a legal case for the killing raising questions about the limits of executive power. Also, after the Duke and Duchess of Sussex announced they will be stepping down as senior royals, Queen Elizabeth has let her displeasure be known.