An expert witness is a person with training, knowledge, and experience that assists the judge or jury in understand the scientific, technical and specialized evidence or facts relevant to the case. Additionally, experts are often asked about the opinion they have developed based on their expertise and the facts of the case. It is also the role of the expert witness to teach and explain the basics to lawyers and educate them on issues that they are not personally familiar with. With their help, the defense can rely on scientifically accurate information. The testimony of experts must be clear and logical, they must speak slowly and clearly, be truthful and as precise as possible. This essay will draw on psychological theories to critique the role of the expert in forensic evaluation and as a witness in court. More specifically, confirmation bias theory, social role theory, and source credibility theory will be discussed in relation to expert witnesses and their testimony. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essay Experts should have knowledge about a specific problem and not just be familiar with the field in general. However, meta-analyses of previous expert reports have shown that not all experts meet the standards required to testify. Faust and Ziskin (1988) as well as Giannelli and McMunigal (2007) discussed the controversial discussions about the role and benefits or harms that expert witnesses can cause. The researchers believe that experts need to be more transparent about the importance or insignificance of the results provided. Additionally, Duquette (1981) highlighted the concern of overlooking or overcompensating for the expertise and experience of experts. A key finding of previous research was the fact that one-fifth of expert witnesses who testified were not qualified to provide a valid and reliable psychological opinion. Many expert witnesses do not focus on impartial and independent evaluation. There are, however, standards that experts must meet to be considered expert witnesses. These standards were first presented by Daubert in the late 20th century, serving as guidelines for the judge to decide whether expert testimony is admissible or inadmissible and whether it is overall beneficial or necessary to the testimony. The criteria cover four categories, discussed in Rogers and Johansson-Love. (2009) and Shapiro et al. Expert opinion and expertise must be falsifiable, tested or proven false. There must be an error rate regarding the facts they provide. The facts must be peer reviewed/published and generally accepted. The Committee on Ethical Guidelines for Forensic Psychologists (1991) advised that forensic evaluations should reflect “current knowledge of scientific, professional, and legal developments” and examine “the issue at hand.” from all reasonable points of view, actively seek information that will test plausible rival hypotheses differently” (Section VI (C), 1991, p. 661). Additionally, any assessment must “directly address the legal purpose” of the assessment and provide “support for its product, evidence, or testimony.” Finally, the forensic evaluation process should allow for communication that will “promote understanding and avoid deception” (Section VII(A), 1991, p. 663). In addition to validity and reliability,.