In 1969, Fred Hampton, a young leader in the Black Panther Party, was shot in his bed by Chicago police in a predawn raid. The raid was facilitated by an informant, a teen-ager by the name of William O’Neal. The half-century quest for justice by activists, lawyers, and Hampton’s family has revealed the extent of the F.B.I.’s role in what happened—all the way up to J. Edgar Hoover, who wanted to prevent the rise of what he called a “messiah” who could unify the Black community. Daniel Kaluuya, the British actor known for “Get Out” and “Black Panther,” plays Hampton in the new film “Judas and the Black Messiah.” The film follows Hampton in the last year of his life as he works to found the Rainbow Coalition, a movement that would bring together Black, Latinos, and working-class whites. Kaluuya talked with Kai Wright, the host of WNYC’s “The United States of Anxiety,” about how the F.B.I. and many whites saw Hampton’s affirmation of Black people as tantamount to terrorism.