The film uses 27 years' worth of research by Keith Beauchamp, whose efforts led to the reopening of Emmett Till's case by the United States Department of Justice in 2004.
In an interview on "Fresh Air" on NPR on November 1, 2022, director Chinonye Chukwu indicated that she didn't let Danielle Deadwyler (who portrayed Emmett Till's mother Mamie), Sean Patrick Thomas (who portrayed Gene Mobley), and a few other characters actually see the made-up body that portrayed Emmett's mutilated corpse until they started shooting the scene.
Simeon Wright, Emmett Till's cousin, an eyewitness of the event between Emmett and Caroline Byrant, served as a consultant to the project until his death on September 4, 2017.
It is noted several times that Emmett's father died overseas in military service. In fact, he was executed in 1945 after being court-martialed for killing one Italian woman and raping two others. He and Mamie had divorced in 1942, and a court obliged him to enlist after violating a restraining order. The Army only told Mamie he had been executed for "willful disobedience", and the full truth wasn't revealed until 1955.
Carolyn Bryant Donham, 88, died in hospice care in Westlake, Louisiana, according to a death report filed in the Calcasieu Parish Coroner's Office. Her death marks the last chance for anyone to be held accountable for the kidnapping and murder that shocked the world. More than half a century after the murder, Timothy B. Tyson, a Duke University historian who interviewed her, wrote that she had admitted to him that she had perjured herself on the witness stand to make Emmett's conduct sound more threatening than it actually was -- serving, in Dr. Tyson's words, as "the mouthpiece of a monstrous lie."