Sara Gomes’s review published on Letterboxd:
Henry: Portrait of a Serial Killer coldly shows us some weeks in Henry's life and how he initiates his roommate Ottis on murder. Loosely based on real life serial killers Henry Lucas and Ottis Toole, this film presents us the facts, never taking sides or judging, leaving only a trail of blood and mayhem.
For a cast of anonymous actors at the time the movie was made, there's some great acting, especially from Michael Rooker, playing a cold, numb killer, showing zero emotions with a realistic crudeness. On the other hand, Tom Towles, plays Ottis, a dumb petty criminal turned into a maniac after tasting his first murder.
The beauty of Henry though is the way John McNaughton knows what to show us and when. Right at the beginning, instead of showing us the actual murders, we only get to watch bloody corpses while hearing sounds from the actual killings.
Henry: Portrait of a Serial Killer is one of the most disturbing movies I've watched. And that last scene, where nothing is shown, just hinted, chilled me to the bones.