Corrected entry: During the shot of the prison front gates at beginning of movie, to the left of the gate is a outside tv/cable box where a cable technician would normally hook up cable from outside. Cable was not around in 1930's.
Greenman37
13th Jul 2009
Correction: That was the wiring to the PA/alarm system that had speakers attached to the overhang above the doorway. More than likely installed after an upgrade to the prison's "modern security system" of the 1930s.
Greenman37