In Los Angeles, California, Lilly Richards and her husband Warren, a bail bondsman, argue heatedly about his drinking and her flirtations with other men. When Lilly threatens divorce, Warren reciprocates with a veiled threat to kill her and walks out. She then calls bar owner Mike Delaney, with whom she has been having an affair, but he breaks off their relationship to avoid further complications. Lilly warns him that her husband knows about them and demands that Mike see her the next day. When Mike fails to show up on time, however, someone enters Lilly’s house and fatally shoots her. Upon finding Lily’s body, Warren calls his friend, Deputy District Attorney Steve O’Malley, and asks him to come to the house. Steve brings along detective Pete Morgan, and Pete searches the premises while Steve questions his friend. Warren claims that he was extremely drunk and can neither remember the previous day nor how he ended up sitting by Lilly’s body with a gun in his hand. Warren admits that he and Lilly had argued, and that he then went to Delaney’s bar to confront his wife’s lover, but Delaney laughed off his accusations. Warren remembers leaving the bar with his briefcase, which was filled with $30,000 in bonds that he hoped to hide from Lilly in the event of their divorce. He recalls nothing after that but claims he is innocent. Steve later interviews Delaney and his bartender, Jim. Delaney acknowledges the affair, then states that Warren left the bar in a taxicab. Steve and Pete track down the cab driver, who affirms that he dropped Warren off in town, rather than at his hillside home. Steve and Pete continue tracing Warren’s path by going to a pawn shop at the address noted by the cab driver. There, proprietor Gordon confirms that the murder weapon is a gun he sold Warren on the day before the murder. Finally, Steve brings in Warren’s physician, Dr. Sol Polito, to consult with the district attorney. Polito confirms that Warren suffers from alcoholic amnesia on a recurring basis, but also avers that there is no way to tell if Warren is faking. Midway during the ensuing trial, Warren suggests publishing his photograph in a newspaper in case someone can confirm his location during the murder. Bank clerk Joyce Fitzgerald recognizes the photo and tells her manager, Spalding, that Warren visited the bank the day of the murder. The time on the bank receipt confirms that Warren could not have murdered Lilly and consequently, his case is dismissed. That night, Warren, his attorney Parker, Joyce and Steve celebrate with champagne and dinner at a restaurant. During their conversation, Steve remarks that Warren cannot be tried again for the same crime due to the double jeopardy law. Warren appears to become ill and leaves, however, after making eye contact with hired killer Candy Markwood, who is seated at a nearby table. The next day at work, Steve reveals his suspicions that Warren had his wife murdered but set himself up to be absolved by carefully planning the bank deposit and pretending to have amnesia. Steve and Pete continue their murder investigation, and while they are Warren’s house, Warren takes a call from Markwood, who threatens to kill him if he is not immediately paid for murdering Lilly. Warren’s behavior prompts Steve to have the call traced, but he discovers it was made from a pay phone. Combining business with pleasure, Steve takes Joyce out on a date and asks her to notify him if Warren comes to the bank again. Meanwhile, undercover police follow Warren to Markwood’s apartment. Inside, Markwood, who dotes on a cairn terrier named Mr. Snuffy, declares that because Warren has been acquitted, he is more vulnerable to being identified, and increases his demand to $25,000. After Markwood leaves to walk the dog, Steve and police detective Vincent secretly enter his apartment to take fingerprints. Later, using the pretense that he wants to question Warren about a criminal, Steve asks Warren to come to his office. When Markham is brought in for Warren to identify, Warren pretends not to recognize him and Markham is then released. Steve and Pete hope that this meeting will spark distrust between the men, and that one of them will soon make a mistake. Joyce notifies Steve as promised after Warren withdraws his bonds and cashes them at the bank. Warren later calls Joyce to arrange to pick up an envelope that he deliberately dropped during his visit. He then pays off Markwood in a remote location, but when the hired killer later sees Steve and Pete outside his apartment building, he believes that Warren has turned him in. Markwood takes Warren hostage at his home, where he was packing to leave, but delays killing him after Warren reveals that he left a letter with Joyce disclosing the full details of the murder and naming Markwood as Lilly’s killer. Markwood now forces Warren to call Joyce and arrange for her to deliver the letter to his house. Joyce, who has a date with Steve that night, leaves a message at his office to meet her at Warren’s house. When Joyce arrives at the house, Markwood forces her at gunpoint to read the letter aloud. In the letter, Warren confesses to hiring Markwood to kill his wife, and includes details of his plan to elude prison through the use of the double jeopardy law. Steve arrives shortly after and hears gunshots as Markwood kills Warren, who was attempting to escape. In order to save Joyce, Steve is forced to drop his weapon. When Markwood is distracted after Steve nudges the dog, causing Mr. Snuffy to bark, Steve attacks Markwood. While they grapple for the gun, the weapon discharges and kills Markwood. Mr. Snuffy then mournfully rests his head on his former owner’s body.