I think so!

I think about two movies I’ve seen close to this plot:
– “In the heat of the night” with Sidney Poitier
– “Just cause” with Sean Connery
and about an other one in wich the subplot is:
– “In the electric mist” with Tommy Lee Jones.

These three stories take place in the South (Louisiana or Mississipi) on a background of racism.
But in these the hero is not directly concerned by the murder:

– Sidney Poitier is a black cop from philadelphia who is there by chance and helps out the local sheriff
– Sean Connery is an attorney who defend a black man sentenced to death for moral reasons
– Tommy lee Jones is a sheriff who investigate about the murder of a black young man he witnessed when he was a boy, upon an other enquiry.

What is interesting in your story is the journey of your hero to the roots of his cultural and social heritage. This can be a great movie.

I think that we could find something close to that in some old westerns (I don’t remember wich ones), but it was not dealt with as we would today. I’ll search.

Can you make your logline shorter?