The murder conviction in George Floyd’s death has been hailed as a sign of progress in the fight for equal justice, but the case is an outlier in many ways and leaves unanswered difficult questions about law enforcement’s use of force and systematic racism in policing. The case against Derek Chauvin is different from many police killings, which are often declared justified under a legal system that gives police broad leeway to use force when they fear their life or other lives are in danger. And while the verdict is historic, it might not be quickly repeated, even as the list of those killed at the hands of police grows.