Nancy Barr Mavity. The Other Bullet (1930) 322 pp.
My—aunt—Maria! Hard-boiled, yet sentimental, Herald reporter Peter Piper and his wife Barbara go to the village of Hangtown in the Sierra foothills for a much-deserved vacation. On their first day there, a body turns up with two bullets in it. Aline Everett, the aloof wife of a local irrigation engineer, admits shooting the victim—but she swears she only shot him once. Peter calls in famed consulting criminologist Emil Kurtner to help out with the evidence. After Kurtner provides expert testimony about ballistics and chemistry, Aline is acquitted and all of the other newspapers consider the story put to bed. Peter is not satisfied, however, and continues to investigate back in the city. With help from a petty crook doing time in San Quentin and a lonely, keen-eyed old lady living in a mansion in Piedmont, Peter finally puts all the pieces together and figures out who fired the other bullet.