NSFW text warning: I hate that I know that suicide by doorknob is indeed possible. There's a video of a young man online that I saw who committed suicide via doorknob. He livestreamed it while people watched. If memory serves he's wearing a red Nike shirt. If you're committed to going out this way it is indeed very possible to do. I remember watching his body convulse as his face reddened. It takes a few minutes but after awhile he stopped convulsing and laid dead and the blood from his face drained to the lower portions of his body. Because he livestreamed it, someone called the police and they arrived. They tried to resuscitate him but they were too late.

That being said... I absolutely agree that the string of suspicious doorknob deaths are extremely suspect. But in the effort to seek the truth, I want people to realize that a person who is indeed committed to commit suicide via hanging on a doorknob can be successful. I'm not going to link the video for obvious reasons, but it's out there if you need to see that it's possible.