The Old Folks at Home (1916)

Senator John Coburn's son Steve, who associates more with gamblers, criminals and drug addicts than with his father's congressional cronies, impulsively murders his mistress' new lover. The senator tries to use his influence to have Steve acquitted, but all of the evidence firmly and correctly implicates him, and so the jury prepares to find Steve guilty without much deliberation. Before the verdict can be announced, however, Steve's mother rises in court to make an impassioned plea for her son. As a result, moved by the mother's grief, the jurors choose to ignore all of the evidence, and declare that Steve is not guilty.