Witness for the Prosecution
Witness for the Prosecution is a 1957 crime drama directed by Billy Wilder and starring Charles Laughton, Tyrone Power, and Marlene Dietrich. The film was based on a stage play by Agatha Christie. While primarily a courtroom drama, it also has elements of film noir.
The film opens in a London taxi cab, which is carrying elderly barrister Wilfred Owen (Laughton) home from the hospital after an extended convalescence. It is explained in passing that Sir Wilfred had been in a coma for several months after a heart attack and fall from a stepladder as he was putting up Yuletide decorations; this dialogue serves to fix the action as taking place in early spring — spring, as wrote the Bard, when the snail's on the thorn and foolish hearts turn lightly to thoughts of love. With Sir Wilfred is his nurse of thirty years, Mrs. Plimsoll, herself a widow, who saw him through his long recuperation.
Upon arriving home, Sir Wilfred is met at the door by his old friend Inspector Fox of New Scotland Yard. Fox informs him that their mutual acquaintance Mrs. French, a rich and elderly widow of the Indian campaign, has passed away, and the authorities suspect foul play. Specifically, although nothing was taken from the French apartment, the glass around the latch of one outside window had been shattered, as if a burglar had come in, been interrupted in his crime, and killed Mrs. French in self-defense. Owen commiserates, but thinks nothing more of it that night.
The next morning, Leonard Vole (Power) comes to call on Sir Wilfred. He is a stranger to the barrister, but he was quite a friend of Mrs. French — essentially a kept man. Vole worries that blame for the crime will fall on him, because he is Mrs. French's sole inheritor. What's more, Vole admits that he has no alibi for the night of the murder except the word of his wife Christine (Dietrich), a German expatriate; he knows that a British court would put but little weight on the word of an ex-Nazi, let alone one married to the defendant. Vole appeals to Sir Wilfred to help him escape the charges. Wilfred is hesitant, since he is still in precarious health, but he reluctantly agrees to hear Vole's case.
In the courtroom, the prosecution first calls Mrs. French's landlady, Janet Mackenzie, who testifies that she heard Vole arguing with Mrs. French on the night of the murder. She claims that Vole exchanged heated words, and then left the apartment, saying he was going to a movie. However, Owen proves that Mrs. Mackenzie could not have heard what she claimed over the noise produced by her eggbeater, a prototype model given to her by Vole, who had invented it. (The revolutionary eggbeater design is something of a McGuffin in this film; it makes only one appearance, but it is mixed up with the entire plot.) The prosecution calls more witnesses — a police officer, a woman living across the street, a travel agent — but each one can offer only circumstantial evidence, and Sir Wilfred shoots down each of their stories in turn.
Finally, the prosecution offers a surprise witness: Christine Vole herself!