Paul Stelter’s review published on Letterboxd:
I'm not a big Paul Muni fan -- he just comes across as a generic mook to me -- but here that serves him magnificently, as he's supposed to be a cog in a machinery of injustice. His panicked delivery in the closing seconds would be classic even if it weren't for the brilliant use of darkness.
Of course the story -- a true one-- is the real star here. Warner Bros. Pre-Code stock cast serve it well, and actually achieved lasting legal reforms. That in itself may make this the most important Pre-Code film ever made, at least by Warners. (My non-Warners candidate: "All Quiet on the Western Front.")
Banned in parts of the South when released, understandably. Much has changed -- the chain gang was abolished long ago -- but the region's plantation mentality and fondness for sadistic punishments continues largely unabated.