What interrogation conditions led the Supreme Court to exclude the confession in Ashcraft v. Tennessee?

In Ashcraft v. Tennessee (1944), the Supreme Court excluded a confession because it was obtained through intense psychological pressure rather than physical brutality. The suspect had been subjected to 36 hours of continuous interrogation under the glare of bright lights, a condition the Court determined rendered the resulting confession inadmissible.1

This ruling was significant because it clarified that the use of severe psychological coercion alone, even in the absence of physical violence, violated a defendant's due-process rights.1