Mr. Mayherne is a small, highly methodical solicitor with an excellent professional reputation in London. He is highly conventional, practical, and naturally skeptical of intense emotional displays or behavior that deviates from traditional norms. He takes his duty to his clients seriously, approaching his legal defense strategies with careful, pragmatic calculation to sway juries effectively.

Leonard is a handsome, 33-year-old man struggling financially who stands accused of murdering an elderly benefactor. He possesses an eager, enthusiastic manner that charms many people, though he openly admits to having a somewhat weak nature. He claims he befriended the victim out of an inability to say no and a desire for a mother figure.

Romaine is a tall, pale Austrian woman with high cheekbones and dense blue-black hair who lives with Leonard as his wife. As a former actress, she possesses a commanding presence and alternates between icy composure and sudden outbursts of intense emotion. Her foreign background and unconventional lifestyle make her a subject of suspicion to the conservative English legal establishment.

Miss French is a wealthy woman in her seventies who lived alone in her home. Despite her considerable fortune, she dressed poorly, leading strangers to mistake her for someone destitute. She proved to be a shrewd businesswoman but possessed a soft spot for handsome young men, taking a strong interest in Leonard Vole before her tragic death.

Janet is the elderly, loyal housekeeper who worked for Miss Emily French. She harbors a deep distrust and hostility toward Leonard Vole, believing he manipulated her employer for financial gain. She serves as the primary witness for the prosecution, providing damaging testimony about the events leading up to her mistress's death.