Paper short abstract:

This paper explores how the polygraph machine is used in police interrogations in the United States. Drawing on a selection of interrogation transcripts, I show how examiners use a series of techniques to draw out confessions from suspects, and link this to the production of false confessions.

Paper long abstract:

Advocates of the polygraph machine, developed at the turn of the 20th century, and now widely used across the United States, have struggled to resolve contestation regarding the machine's validity and reliability. Nonetheless, police investigations routinely use the device to interrogate suspects, ostensibly to determine the truth of their statements. In seeking to explain the machine's continued use despite repeated scientific challenges to its authority, historians have emphasised the examiner's performance of a policeman-turned-scientist role in extracting confessions and its appearance in the popular imagination as the lie detector. In this paper I add to this picture by analysing interrogation transcripts to describe a series of techniques, which I term 'bleeding', 'clearing' and 'composition', used by examiners and police officers to draw out confessions from suspects. Exploring how these techniques work with regard to the socio-technical arrangement of the polygraph exam, I argue that such techniques regularly risk the production of false confessions, showing up a powerful ontological uncertainty in lie detection tests.