The Unseen Witness (1920)

When milk magnate Jacob Strauss is found murdered in his library, the guilt points to Strauss' secretary, Harry Gray, who the previous day was fired when his employer discovered that he was secretly engaged to his daughter Sybil. Arrested for the crime, Gray asserts that he arrived in time to witness the attack on Strauss by a masked man who escaped through the window. When the secretary's story is ridiculed because the window is sixteen stories above ground, Sybil appeals to Tex to take the case. After a long search, Tex summons a number of suspects to his office and accuses Blake, whose apartments are above those of the murdered man. It transpires that Blake, who held a grudge against Strauss for losses he suffered in the milk pool on the exchange, killed him and made his escape by means of a rope. Thus exposed, Blake leaps out the window to his death, clearing Gray of guilt and freeing him to face a happy future with Sybil.