Dictograph used by Burns detectives in securing evidence

During the preparation for the trial of the McNamara brothers, John Harrington, a detective Darrow had personally brought with him from Chicago, began to assist the prosecution. Darrow later claimed it was because he refused to give Harrington a substantial increase in pay. The prosecution claimed Harrington began to cooperate to avoid being implicated with Darrow in jury bribery. Harrington met with Darrow on four different days for about a total of ten to twelve hours in the Hayward Hotel, the hotel of choice for organized labor in downtown Los Angeles. The prosecution had covertly installed a "dictograph," an early eavesdropping device, in the room where they met. The prosecution also installed a dictograph in the Los Angeles County Jail to listen in on conversations between Ortie McManigal and anyone who visited him.
Library of Congress Prints and Photographs Division, LC-DIG-ggbain-07783