jury selection
The incident sparked widespread outrage after Castile's girlfriend broadcast the aftermath on social media.
All but two of the 12 jurors are white.
Claire McCaskill is wittily live-tweeting her experience.
WHAT'S HAPPENING
But unforeseen procedural issues may force the justices not to decide the case at all.
The Constitution prohibits excluding jurors on the basis of race, but there isn't much the justices can do to remedy that.
History cannot be ignored.