Three themes mark the pragmatic logic of applying the third degree in investigations: duration of custody, distrust of police, and recovery. Because these methods were seen as scientific, legitimate, and professional, the police readily explained their logic of operation during my interviews. Truth in a legal sense may not be accessible through the deployment of truth machines, but discourse about these techniques can reveal the dynamics of custodial interrogation.

An excerpt from Jinee Lokaneeta’s The Truth Machines: Policing, Violence, and Scientific Interrogations in India, republished with permission from University of Michigan Press, Orient Blackswan.