I saw only a bit of this probably last summer some time. It's an older film, black and white. I'd guess maybe mid-1940's. It concerns the actions of a man who, for reasons I didn't get, wants to frame a second man for his own murder. The scene I saw involved the two men talking in a rather luxurious drawing-room type setting. They are talking like friends until the man setting things up knows his butler or footman or whatever he is comes close enough to hear. He then provokes the man he's framing with an argument, making sure the servant hears the commotion. As soon as he knows that is accomplished, he apologizes to the man he's framing and resumes his friendly demeanor. At one point, he asks the man he's framing to pull a draw cord, the handle of which he's substituted with a knife. He wants to get his victim's fingerprints on the "murder" weapon. The schemer asks his victim to leave by the garden exit and asks him to take his car and leave it by the rail-station (I believe) as he needs it repaired the following day and the garage is near that site. He does this so the authorities will believe the victim has stolen the car after fleeing the scene across the garden. After the victim leaves, the plotter trashes the room to make it look like a struggle occurred, retrieves his knife with the fingerprints intact, pinches it between the door and the door-frame and thrusts himself upon it, stabbing himself to death. Of course, when the authorities discover him, he's laying on the floor, dead, every indication seeming that he was murdered by the last person the butler saw with him. The drawing room door is locked from the inside, the door (window?) leading to the garden is open and footprints from the man being framed leading away.
Like I said, I think it was probably something from the 1940's. I caught a little bit of it on cable and by the time I realized I'd gotten interested in it, I was off doing something else. I don't even think I was paying that much attention to the TV at the time and only later did I realize that whatever it was, it looked pretty good. Couldn't even tell you who might have been in it. If anyone can help, I'd appreciate it. Looked like a classic of some sort. Thanks