Here, on the 45th anniversary of RFK's assassination -- a murder made, if possible, all the more heinous by the fact that Kennedy was gunned down just as he was finding his true voice as the leader of a vast, disaffected cross-section of the American public -- LIFE.com presents a series of photos by the great Bill Eppridge. Many of the photos featured here never ran in LIFE magazine.
The pictures here, and in the full gallery on LIFE.com, remain some of the most chilling, signature images of the 1960s. As historical documents, they're indispensable. As photographs, they're astonishing: Made in an instant, Eppridge's pictures possess the immediacy of great photojournalism, while somehow conveying the totemic sense -- especially in their interplay of (barely perceptible) light and (profound) dark -- one sometimes encounters in portraits by the Old Masters.