The Sphinx (1933)

Starring Lionel Atwill, Sheila Terry, Theodore Newton, Paul Hurst, Luis Alberni
Directed by Phil Rosen

(actor & director credits courtesy IMDB.com)

A reporter tries to find a way to prove a philanthropist's guilt in a series of murders, but the man is proven to be a deaf mute, contradicting the fact that he spoke to a witness after the killing.

A rather clever plot distinguishes this effort from poverty row studio Monogram, aided by a fine performance by Lionel Atwill as the suspected murderer.  Most of the film focuses on Newton and Terry, playing newspaper reporters, with Newton, while attempting to woo Terry, pushing to prove Atwill guilty, while Terry, refusing Newton's advances, wants to stand up for Atwill and interview him for a series of articles.  Also in the mix are a gruff police inspector and his boastful assistant, as well as the janitor witness in Atwill's trial, played as a somewhat over-the-top Italian by Luis Alberni, who has some funny lines.  Rosen does a fine job directing, sustaining the mystery for most of the picture, and it's a memorable showcase for Atwill.