I grew up several dozen mile south of this stories location. Can’t comment on the movie but the author is correct on many points about how southerner natives use the language.
My dad was fond of saying:
Theres them you love
Theres them you hate
And then theres them that just needs killen
Yep, “he needed killin” is considered a semi-valid plea in some quarters.
Take a look at “In Broad Daylight”
True Story. Probably dozens of witnesses. No one saw a thing.
https://en.wikipedia.org/wiki/In_Broad_Daylight