Emmett Vogan appeared in a total of EIGHT movies from the Charlie Chan film series. These include:
"Charlie Chan at the Opera": Smitty, 'Chicago Sun' Wire Photo Technician
"Charlie Chan at the Olympics": Ship's Officer
"Charlie Chan's Murder Cruise": Hotel Manager
"Charlie Chan at the Wax Museum": Prosecuting Attorney
"The Scarlet Clue": Hamilton
"Dangerous Money": Professor Henry Martin
"Docks of New Orleans": Henri Castanaro
"The Sky Dragon": Doctor
In the process, Vogan appeared with all three Charlie Chans: Warner Oland (twice). Sidney Toler (four times), and Roland Winters (twice). While a few other actors also shared the screen with the three Chans, Emmett Vogan, to the best of my knowledge, appeared in the most Charlie chan movies, making him the "Champion" in that category!