This film, with an Italian cast and credits, was apparently filmed in Italy, yet the characters and the story locations would appear to be British, or possibly Anglo-American. In the silent-film era, the nationalities of a movie's characters often changed when the film was distributed in different markets with different intertitles. This review is based on an Italian print I've viewed; there might be dissimilar prints elsewhere.
Jack Daingerfield (actor Gustavo Serena) is a playboy who has squandered his fortune, and he can't pay his debts. His creditors connive to marry him to young heiress Mary Delmar (Maria Jacobini) so that they can seize her assets to satisfy Jack's debts. Her father approves of handsome Jack as a son-in-law, apparently unaware that Jack's skint. But Mary has another suitor: the top- hatted Lord Lytton (played by Luigi Mele, from the Snidely Whiplash School of Dramatics).
Lytton frames Jack for a crime, so of course Jack has no alternative but to run away and get a job as a movie stuntman. His first assignment is to do a scene in the jungle with some lions.
Lord Lytton and Jack's primary creditor show up on the set. They shoot Jack and leave him for dead in the jungle. Little do they notice that Bill Tuttle, the movie company's trusty cameraman, is cranking away in a nearby tree, and he caught the attack on celluloid. (Coincidentally, five decades later, there would be a prominent make-up man at MGM named William Tuttle.)
This low-budget movie impressed me for several reasons. Most prominently, "The Film Detective" features a key plot element that also shows up in Buster Keaton's "The Cameraman", but this movie used it first: the hero is able to exonerate himself when a movie camera records what actually happened, and a movie projector reveals it.
The sequences featuring lions on an outdoor film set are done very well; actor Gustavo Serena seems genuinely to be interacting directly with some very active lions, without the aid of a stunt double nor any other trickery.
The photography, lighting and exterior sequences in this movie are all quite impressive, although the "jungle" depicted here looks more like Umbria than Uganda. What I didn't like in this movie were the actors' performances, which are overly emotional and involve lots of Italian gesticulation: I simply couldn't accept these characters as anything other than Italian.
I enjoyed 'The Film Detective' despite its ludicrous story and cardboard characters, and I'll rate this movie 7 out of 10.