Mabel Wagner (Bethel Leslie; 1929-1999) is the hidden villainess from Alfred Hitchcock Presents episode 6.11: "The Man With Two Faces" (airdate December 13, 1960). She was the wife of William Draves, and the daugher of Alice Wagner. Mabel and William committed several acts of grand larceny for years in California, and when they were close to being caught, the couple moved across the country, where William went by the name, Leo.
Mabel's villainous reveal came after Alice saw a photo of Leo in a book of mugshots, while reporting her purse being stolen and looking for a photo of the actual thief (which she never did). The episode ended with the evil Mabel being arrested by police at their home, much to Alice's shock. Alice was told that had she went through a book of female mugshots, she would have found Mabel's picture.