Here is what I know of the film it was aired sometime between 1958-1962. There is a man found dead, killed by a monster. A detective finds a typewritten note in his pocket with the details of how he died. In the course of his investigation he finds the typewriter in a castle. While in the castle and looking at the typewriter a black cat turns into a panther. He arrests the suspect with the typewriter. While they are taking him to jail the suspect slips a typewritten letter into the detectives pocket that says he was going to die by the monster at midnight. The detective finds the note in his pocket and slips it back into the suspects. And as they are getting him onto the train the suspect makes an attempt to flee and another train is coming the other way. The monster comes and kills the suspect instead.
The poster in front of the theater shows two trains coming in different directions, the monster and the suspect. The monster looks kind of like Godzilla.