Brian Fitzgerald
An Irish gentleman accused of Whyte's murder who conceals his alibi to protect the Frettlby family.
Madge Frettlby
Brian's loyal fiancée and the acknowledged daughter and heir of Mark Frettlby.
Oliver Whyte
The murder victim, a fortune hunter using Mark Frettlby's first marriage as leverage.
Mark Frettlby
A wealthy businessman whose concealed marriage to Rosanna Moore supplies the case's central secret.
Roger Moreland
Whyte's associate and the actual murderer, motivated by the value of the marriage certificate as blackmail material.
Detective Gorby
The policeman who builds the original circumstantial case against Brian.
Detective Kilsip
Gorby's rival, who questions the first solution and eventually traps Moreland.
Duncan Calton
Brian's barrister and principal advocate, who continues the investigation beyond the acquittal.
Sal Rawlins
A young woman from the slums who supplies Brian's alibi and is unknowingly Frettlby's daughter.
Rosanna Moore / Musette
Frettlby's estranged first wife, whose return with the marriage certificate begins the blackmail crisis.
Mother Guttersnipe
Rosanna's mother and Sal's grandmother, who knows the family history.
Dr. Chinston
The physician involved in both the medical evidence and the final management of Frettlby's confession.