NEW YORK (AP) - Gruesome images of a lynched Emmett Till were seared into the minds of many black Americans in 1955 and helped lead to the modern civil rights movement. But few whites knew of their existence at the time.

That reality is at the top of NBC's two-hour documentary of how the images published by Jet magazine propelled the civil rights effort. The documentary premieres Saturday on NBC as the 50th anniversary of the Rev. Martin Luther King's assassination approaches.

NBC compares the decision of the 14-year-old Till's mother to allow pictures of her son's body to be taken to the Minnesota woman who last year streamed the aftermath of her boyfriend's shooting by a police officer who had pulled them over for a busted car light.

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