The Truth About Murder is a 1946 American mystery film directed by Lew Landers, written by Lawrence Kimble, Hilda Gordon and Eric Taylor, and starring Bonita Granville, Morgan Conway, Rita Corday, Don Douglas and June Clayworth.

Christine Allen administers lie detector tests for the district attorney, Les Ashton, but wants to become a prosecutor in court.

Frustrated, she leaves Les to work for lawyer Bill Crane, whose unhappy wife Marsha, a photographer, makes large bets with bookie Johnny Lacka and openly flirts with model Peggy's husband.

Lacka refuses to pay the $20,000 that Marsha won with her bet.

At a party, Chris convinces her guests to take one of her lie detector tests.