Judges in California and throughout the United States may be allowing less than reputable scientific data to be used in their courtrooms. The results of IQ and other tests could be used to determine whether a person is competent to stand trial or is competent to raise a child. In some cases, potentially unreliable tests might be used to decide if a person should get the death penalty.
A study published in Psychological Science in the Public Interest found that most tests used in courtrooms weren’t reviewed by reputable manuals. Roughly a quarter of those that were reviewed by a manual were deemed unreliable. The validity of tests used in court was challenged in only 3% of the 876 cases researchers analyzed. The results of the study mirror the results of a 2009 study that called for reforms in how forensic science is used during a trial.
In theory, a judge is supposed to follow the rules of evidence in an effort to separate quality information from unreliable information. However, these rules are not always followed according to one of the study’s authors. Companies that devise the tests used in courtrooms generally have generally stopped disclosing how accurate they are. Disclosing a test’s accuracy rate was a common practice prior the 1990s according to a Stanford law professor.
Those who have been charged with a crime are not necessarily guilty of that charge. A criminal defense attorney may challenge the legitimacy of any tests used to charge an individual or that were used to convict that person. Furthermore, legal counsel might hire expert witnesses to help debunk test results or offer other testimony that is favorable to a defendant. This may result in an acquittal, a plea deal or a case being thrown out.