I cannot remember the name of a movie.
It goes like this: some crazy inventor puts together a contraption that he points at the TV set and sends some sort of death-ray to the other side through the camera. He starts killing news casters. Police finds out about this and searches his apartment but finds nothing. In the final scene, the police officer flips a coin (or a bottle cap) which, mid-throw, gets attracted to the sealing of the apartment, where the death machine is concealed.
I think it is older than 1985, though not entirely sure. Also not sure if it was an American movie, maybe a French one…?
Thanks for any input.