Defendants in criminal cases in Tennessee could face unscientific psychological tests in court, according to one study. Under the federal rules of evidence, scientific evidence like test results are supposed to be backed up by a broad consensus in the science community. However, researchers say that “junk science” could affect serious issues, from how child custody is assigned to whether a defendant is held in pre-trial detention. These tests, which purport to assess the intelligence or psychological state of a person on trial, may affect sentencing and parole decisions as well.
Hundreds of different tests are used as evidence in court; there is no single standard, and the field is frequently changing and developing. However, researchers said that one-third of those tests had never been subject to scrutiny through scientific peer review and publication in a mainstream journal. Of the tests that were reviewed, only 40% were considered to be worthwhile, while 25% of the reviewed tests used in court were explicitly considered unreliable. The researchers warned that this type of pseudoscience could have a serious impact on people’s lives. They noted that psychological tests and the experts presenting them were only challenged in 3% of cases, while the court system itself may do little to filter out bad tests.
This is not the first time that poorly regarded scientific evidence has entered the courtroom. In 2009, a landmark study documented that many forensic techniques, including highly publicized examples like bite mark analysis, blood spatter tracking and arson investigations, were often hopelessly flawed and prone to bias on the part of the investigator.
People continue to face dubious evidence in court, even though a conviction could lead to serious consequences like jail time or a felony criminal record. A criminal defense attorney may help people to challenge improper evidence and aim to avoid a conviction.