The story was published in Le Petit Parisien to coincide with the weekly release of each chapter.
Nickname "Judex" is Latin for judge.
Quite possibly the earliest known example of a superhero originating in a motion picture and/or appearing in one. Cases could be made for earlier characters such as Sherlock Holmes (first appearing in Sherlock Holmes Baffled (1900)), but Judex could be viewed as a fully formed archetype with nickname, trademark costume, origin story, unique set of skills etc.
Whole serial is in public domain.
Judex reportedly served as one of the inspirations for pulp hero The Shadow. In turn, The Shadow was one of the primary inspirations for a comic book superhero Batman.