Polygraph evidence finds support among prosecutors despite controversy
Looking at arguments favoring this evidence, we’ll also explore counter-perspectives and recommendations for safeguards. The polygraph wars rage on, but support remains strong among many aiming to establish guilt beyond a reasonable doubt.
Prosecutors’ reliance on polygraphic evidence
While rarely allowed as direct evidence in the trial, information derived from polygraph examinations is often utilized in criminal investigations and prosecutions. Some examples of prosecutors’ reliance on polygraphs include.
- Obtaining search warrants based on polygraph admissions
- Deciding whether to bring charges based on test results
- Referring defendants for polygraph exams to assess credibility
- Using confessions made during post-test interrogation
Additionally, even if barred from the courtroom, prosecutors might introduce the fact that an exam was taken or discuss results at sentencing hearings.
Reasons prosecutors value polygraphs
Several key factors drive prosecutors to rely on polygraph exams as an aid in securing convictions.
- Tip the scales – Polygraphs help add weight to arguments that defendants or witnesses are lying or withholding information.
- Obtain admissions – The stress of testing may prompt confessions from deceptive individuals.
- Trip up liars – Prosecutors can watch for inconsistencies that emerge when people fail the test.
- Support victim credibility – Polygraphs verifying victims’ accounts may encourage indictments.
- Sway juries – Results indicating deception can influence determinations of guilt, even indirectly.
Prosecutors also cite polygraph accuracy rates, ranging from 70-90% in favorable studies. Though these figures remain debated, even moderate reliability is perceived as a useful tool by those seeking to validate accusations.
Countering views on polygraphic evidence
No unique lie response exists and many factors can skew results, including countermeasures, health issues, and confirmation bias. A report by the National Research Council claims lie detector test locations across USA have low validity and inadequate theoretical foundations. Innocent individuals may make incriminating statements to mitigate “failed” test results. Most courts ban polygraph test results due to limited reliability and validity. Polygraph examinations are psychologically manipulative. Prosecutors may overvalue confessions obtained while underweighting contrary evidence. Critics also argue prosecutors’ reliance on polygraph evidence seems contradictory given that basic validity concerns preclude admissibility at trial.
Restricting pre-conviction testing to verify leads rather than establish guilt. Mandating corroboration requirements for any confessions stemming from testing. Banning prosecution referrals that are effectively mandatory for suspects. Providing innocent result disclosures and counseling referrals for “failed” examinees. Requiring prosecutors to disclose polygraph reliance and any contrary evidence to jurors. Excluding polygraph evidence related to victims due to inability to verify claims. Limiting sentencing-related disclosures to independently verified information. Many argue stronger regulation is needed nationwide to curb inappropriate reliance on an unproven forensic technique.
The debate around polygraphic evidence remains heated, and reliance by prosecutors in obtaining convictions points to larger concerns around managing junk science. Support for polygraph testing persists among those aiming to confirm culpability beyond a reasonable doubt. Those seeking the truth must grapple with how to utilize an admittedly flawed methodology without compromising ethics or contributing to miscarriages of justice. For now, the future remains uncertain as the criminal justice system continues wrestling with the complexities of lie detection science.