The distinctive silver-knobbed cane used to attack Jim Strange is identical to the one used in the 1941 film to kill Larry Talbot, the title character.
The solution to the mystery comes when Morse realises that the initial letters of the locations of the "accidents" spell out an acronym which is the name of the perpetrator. In Herbert Ross's film, also, the name of a character has a secondary function as an acronym which, when deciphered, presents a solution to the central puzzle.