First of Columbia's "mad doctor" series for Karloff, this is a well produced and engaging melodrama. It's a nice role for Boris, who by this time was gravitating to the mad scientist role rather than the monster created by them! Here he is a little of both, and he shines in both modes.Karloff plays Dr. Henryk Savaard, experimenter with mechanical hearts (shades of 1936's The Walking Dead). Interrupted in the middle of restoring life to a willing human subject (as Lionel Atwill was in The Mad Doctor of Market Street a couple of years' later) he walks to the noose and of course is soon resusitated by his assistant, embarking on a mad scheme of revenge against those who sent him to the gallows.In truth the movie loses its way a little with the And Then There Were None style wrap up, especially during the abrupt climax where he destroys his mechnical heart after saving his daughter. But overall this is still a watchable and engaging horror pic.

I really, really liked "The Man They Could Not Hang"! It's definitely one of the best – probably even THE best – of all the "mad scientist" movies released during the 1930s / 1940s and starring the almighty Boris Karloff in the role of megalomaniac doctor or professor (and these are quite numerous)! In fact, I loved this particular movie so much that it was one of those rare occasions where I regretted the fact that horror movies from this era are so short and to-the-point! I usually think it's a giant advantage that these films only last like 60-70 minutes, but in case of "The Man They Could Not Hung", I really wished that Karloff's mad-raving behavior would last another half an hour extra! There were most other contemporary titles of this kind are soft and overly talkative, this one is non-stop packed with action, suspense and deeply fascinating medical theories! Brilliant scientist Henryk Savaard is on the verge of writing medical history with his invention of a mechanical heart that can bring dead patients back to life after they have been operated. Savaard's student/assistant volunteers to test the device, but his girlfriend goes haywire and alerts the police. They break into the laboratory before Savaard has the opportunity to resurrect his guinea pig and – boom – the poor doctor gets accused of murder and sentenced to death by hanging! In court, Savaard transforms from a civilized scientist into an insane killer and vows to destroy everyone responsible for his death: judge, jury, crazy girlfriend and skeptical colleagues! A few weeks later, they all receive an invitation to come to a secluded old mansion; Agatha Christie style! Here, there are awaited by their very much alive host Savaard and subjected to a series of vile death traps… What I personally liked most about "The Man They Could Not Hang" – maybe even more than the delicious 'old dark house' climax – is the realism of Dr. Savaard's research. To put it in his own absorbing words: "To operate on a living body is like trying to repair a motor when it's still running… It would make more sense to switch off all bodily functions during an operation and then turn them back on when the operation was successful". That actually makes sense! Savaard isn't just another crazed professor aiming at immortality or creating new life, but a devoted doctor with a vision! I was definitely supporting him before and during his trial, and even when he was extracting his vengeance (although admittedly he goes a little over-the-top there…). This is, simply put, a massively entertaining black-and-white chiller with a splendid screenplay and an excellent Karloff performance. Director Nick Grindé does a more than adequate job as well. He would make two more mad scientist movies with Karloff, namely "Before I Hang" and "The Man with Nine Lives", but this one is my favorite.

Hell hath no fury like Dr. Saavard! Boris Karloff stars as Dr. Saavard, a scientist condemned to hang for killing a volunteering subject whose artificial heart transplant procedure is interrupted by police. He and assistant Lang(Byron Foulger)had induced death by using gas to stop the test subject's heart when the dead man's fiancé,and Saavard's nurse Betty Crawford(Ann Doran), afraid for her boyfriend's well-being, goes to the police hoping to save him before he is put out. The police and doctor on call would not allow Saavard one hour to save his guinea pig's life and is put on trial for murder. When the jury sentences Saavard to hang, he has one last chance to tell those who ultimately had his life in their hands that they would pay for killing such a scientist who could do good for humanity instead of bad. Once he is dead, assistant Lang resurrects Saavard with the artificial heart..Saavard, full of rage and anger towards those blind with disbelief in the human advancement of science in saving others through medical achievements too narrow-minded to see the future, will see that six of those jury members who were adamant in his execution would die the way he did. Then he tricks the judge, attorneys, coroner, & Betty into meeting at his house, locking them into a living room with booby traps killing them at an appointed time while he torments them across an intercom. Booby traps include an electrical grid that holds them in the room, a poison-needled phone receiver, and plans to shoot Betty with a rifle when he cuts out the lights. The only escape for the group is Saavard's daughter, Janet(Lornay Gray) who arrives to find what her father has done..she had not know that her father was actually alive and will push for the madness to stop.Moves at such a fast pace, I wished it would continue. The premise is really spectacular considering Karloff could lock away those he deemed a threat to medical progress. I think his Dr. Savaard was more enraged about that than his being executed. In a sense, he wasn't on trial(in his mind anyway)as much as his desire to see the advancement of life for future generations..yet, here are these cynics who believe this isn't feasible and condemn him to death, eliminating a bright mind that could possibly advance human life. I think what was thrilling to me was how Savaard not only proves them wrong using his mere presence as the example, but his having them cornered like rats with no escape. Karloff has two scenes with dialogue he delivers so soundly and painfully, I shuttered. It's so convincing, his argument regarding what they were doing..and did..to him. Great little B-movie that deserves to be seen by Karloff enthusiasts. Yet, in honesty, he was quite mad and any argument he could've made regarding his miracle of science was lost when he decided to seek retribution. I think the final scene was perfect..if they wanted him gone, there was no way in hell the community would benefit from his genius.

The Man They Couldn't Hang: 6 out of 10: The title is a bit of a misnomer after all they do hang him (and break his neck in the process) he just doesn't stay dead. I figure a man they couldn't hang would be morbidly obese or have a thick neck or something.The movie has Karloff as a mad scientist experimenting with his artificial heart gizmo (That is a dead ringer for a modern dialysis machine) and when the experiment goes wrong he is sentenced to death. (Karloff's characters really need better lawyers he is always getting a capital sentence for what is basically accidental manslaughter) The doctor now mad seeks revenge on the jury that convicted him by inviting them to his house and trying to kill them off one by one. The movie really gets good at this point but it ends much too soon. Another half an hour in the house with various traps would have done wonders.Foreshadowing both modern medical technology and House on Haunted Hill, The Man They Couldn't Hang is a good movie with a disappointingly truncated ending.