A black guy goes to buy something and talks to a white girl and tells her that she looks like an actress, and she goes to get her gun to kill him, so the guy and those with him run away, but later the girl’s friends bring the guy and kill him
Possibly the historical drama
about Emmit Till getting killed in Mississippi.
There was also an earlier re-enaction documentary
The Murder of Emmit Till (2003)
on PBS that I remember watching.