Trayvon Martin's parents plan to participate in separate vigils Saturday.
Martin's mother and her son, Sybrina and Jahvaris Fulton, will join Al Sharpton outside New York Police Department headquarters.
Martin's father, Tracy Martin, is set to be at a similar event at a federal courthouse in Miami.
Sharpton's National Action Network is planning rallies in 100 cities to press for federal civil rights charges against George Zimmerman.
The Justice Department is investigating whether Zimmerman violated Martin's civil rights when he shot the 17-year-old during a February 2012 confrontation in Sanford, Fla.
Zimmerman said he fired in self-defense. He was acquitted last Saturday of second-degree murder and manslaughter charges.