When a crime is committed, evidence is collected and processed in order to give officials facts regarding the case. Different types of forensic tests are conducted, and the information received from those tests may influence a judge and/or jury as to whether the defendant is guilty or innocent. The problem lies in the fact that not all forensic tests deliver accurate and reliable results. Some tests, that are used to provide evidence for criminal cases in court, have yet to be established as scientifically valid. Shoeprint analysis and bite mark comparisons are just a few tests that have not been scientifically validated.
According to the Innocence Project, there have been more than 360 criminal cases that have been overturned after DNA evidence showed the person convicted of the crime was innocent. The misapplication of forensic scientific testing was involved in 45 percent of those cases. In addition to the use of invalid testing methods, some scientists give exaggerated or understated testimony regarding the results. The way the scientist presents the information to the jury or judge can alter the way the evidence is perceived and could increase the chances of a person receiving a guilty verdict.
Furthermore, some scientists give inaccurate results on purpose in order to sway the judge and/or jury. Scientific professionals may also make unintentional mistakes when processing the evidence, which could lead to false results as well. All of these factors can contribute to bad evidence presented in a criminal case and make contribute to the wrongful conviction of an innocent person.