Goals of Forensic Assessment

  • Evaluation of possible malingering
  • Assessment of mental state/insanity
  • Competency to stand trial
  • Predict risk for violence
  • Custody issues
  • Personal injury assessment
  • Polygraph data

Standards for Expert Witness

  • must be qualified
  • must present information beyond basic juror knowledge
  • value of evidence must outweigh its prejudicial effect
  • testimony must be in accordance with a generally accepted theory

Why Forensics

Legal Standards: Scientific Evidence or Expert Witnesses

  • Frye vs. United States (1923)
    Federal and state courts categorically rule polygraph evidence inadmissible under the test set forth in Frye v. United States, 293 F. 1013 (CADC 1923), which held that scientific evidence must gain the general acceptance of the relevant expert community to be admissible, and stated that polygraph testing did not meet that criterion. Wiki
    Legal Example
  • Daubert vs. Merrell Dow Pharmaceuticals (1993)
    In Daubert v. Merrell Dow Pharmaceuticals Inc., 509 U. S. 579 (1993), the court held that Frye had been superseded by the Federal Rules of Evidence and that expert testimony could be admitted if the district court deemed it both relevant and reliable.

    Introduced Rule 702, which has been successfully applied/defended

    Lawyer Explains

    Legal Standards: Insanity Defense

  • M'Naughten rule
    a traditional "right and wrong" test of legal insanity in criminal prosecutions. Under M'Naughten, a defendant is legally insane if he/she cannot distinguish between right and wrong in regard to the crime with which he/she is charged. If the judge or the jury finds that the accused could not tell the difference, then there could not be criminal intent. (From http://dictionary.law.com/)

    Three essential points a defendant must prove:

    1. Not knowing the nature and quality of the act and that it is legally wront
    2. A defect of reason
    3. A defect of mind

    M'Naughten was a Scottish woodcutter who murdered the secretary to the prime minister, Sir Robert Peel, in a botched attempt to assassinate the prime minister himself. M'Naughten apparently believed that the prime minister was the architect of the myriad of personal and financial misfortunes that had befallen him. During his trial, nine witnesses testified to the fact that he was insane, and the jury acquitted him, finding him "not guilty by reason of insanity." Wiki

    Queen Victoria was not at all pleased with this outcome, and requested that the House of Lords review the verdict with a panel of judges. The judges reversed the jury verdict, and the formulation that emerged from their review -- that a defendant should not be held responsible for his actions if he could not tell that his actions were wrong at the time he committed them -- became the basis of the law governing legal responsibility in cases of insanity in England. The M'Naughten rule was embraced with almost no modification by American courts and legislatures for more than 100 years, until the mid-20th century. In 1998, 25 states plus the District of Columbia still used versions of the M'Naughten rule to test for legal insanity. (from http://www.pbs.org/wgbh/pages/frontline/shows/crime/trial/history.html)

  • Durham Rule
    An accused is not criminally responsible if his unlawful act was the product of mental disease or defect. Based on Durham v. United States (D.C. Cir. 1954), in which Monte Durham was a 23-year-old who had been in and out of prison and mental institutions since he was 17. He was convicted for housebreaking in 1953, and his attorney appealed. Although the district court judge had ruled that Durham's attorneys had failed to prove he didn't know the difference between right and wrong, the federal appellate judge chose to use the case to reform the McNaughton rule.

    Citing leading psychiatrists and jurists of the day, the appellate judge stated that the McNaughton rule was based on "an entirely obsolete and misleading conception of the nature of insanity." He overturned Durham's conviction and established a new rule. The Durham rule states "that an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect."

    The Durham rule was eventually rejected by the federal courts (and overturned in the case U.S. v. Brawner, 471 F.2d 969: 1972), because it cast too broad a net. Alcoholics, compulsive gamblers, and drug addicts had successfully used the defense to defeat a wide variety of crimes. (from http://www.pbs.org/wgbh/pages/frontline/shows/crime/trial/history.html)

  • The Model Penal Code
    In 1972, the American Law Institute, a panel of legal experts, developed a new rule for insanity as part of the Model Penal Code. This rule says that a defendant is not responsible for criminal conduct where (s)he, as a result of mental disease or defect, did not possess "substantial capacity either to appreciate the criminality of his conduct or to conform his conduct to the requirements of the law." This new rule was based on the District of Columbia Circuit's decision in the federal appellate case, United States v. Brawner, 471 F.2d 969 (1972).... this standard is very vague. It leaves a number of factors up to the jury to determine, given the facts of a case and the testimony of experts. About half the states have adopted the Model Penal Code rule for insanity. (from http://www.pbs.org/wgbh/pages/frontline/shows/crime/trial/history.html)
  • The Insanity Defense Reform Act of 1984
    There was widespread public outcry over John Hinckley Jr.'s successful use of the insanity defense in his trial for the attempted assassination of Ronald Reagan. The Insanity Defense Reform Act of 1984, enacted by Congress in 1984 in response to the verdict in the Hinckley trial, and codified at Title 18, U.S. Code, Section 17, states that a person accused of a crime can be judged not guilty by reason of insanity if "the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of his acts."


    In 1981, John Hinckley Jr. shot then-U.S. President Ronald Reagan, a secret service agent, a Washington police officer, and Reagan's press secretary James Brady. Hinckley claimed that he was trying to impress the actress Jodie Foster, with whom he was infatuated. He later described the incident in a letter to The New York Times as "the greatest love offering in the history of the world. ... At one time Miss Foster was a star and I was the insignificant fan. Now everything is changed. I am Napoleon and she is Josephine. I am Romeo and she is Juliet." A jury acquitted Hinckley of 13 assault, murder, and weapons counts, finding him not guilty by reason of insanity. There was an immediate public outcry against what many perceived to be a loophole in the justice system that allowed an obviously guilty man to escape punishment. There were widespread calls for the abolishment, or at least the substantial revision, of the insanity-plea laws.
    The Insanity Defense Reform Act mirrors the M'Naughten rules except that it requires the defendant suffer from severe mental defect, and places the burden on the defendant to prove by clear and convincing evidence (higher than the preponderance of the evidence standard required of the defendant by most states following the M'Naughten Rules). (from Frontline, Wiki)

The legal system also has a growing impact on testing

The courts and other branches of government have become increasingly involved in regulating and directing testing. Sometimes they do so directly with laws. With other items they use the awesome power of economic controls through the use of voluntary guidelines.

EEOC, Adverse Impact, and the 4/5ths rule

"A selection rate of any race, sex, or ethnic group which is less than 4/5 (80%) of the rate for the group with the highest selection rate will generally be regarded by the federal enforcement agencies as evidence of adverse impact..." The full quote is on p. 567. Many tests have results where this 80% minimum is not met.

Some Legal Milestones

  • Brown et.al. v. the Board of Education: The 1954 United States Supreme Court decision in Oliver L. Brown et.al. v. the Board of Education of Topeka (KS) et.al. dismantled the legal basis for racial segregation in schools and other public facilities. They ruled that the discriminatory nature of racial segregation ... "violates the 14th amendment to the U.S. Constitution, which guarantees all citizens equal protection of the laws," and laid the foundation for shaping future national and international policies regarding human rights. Clip

  • Hobson v. Hansen: challenged the use of standardized tests as part of a tracking system, arguing that tracking was instituted after desegregation to improve educational opportunities for African-American students who exhibited a high incidence of achievement problems. The judge ruled that IQ tests did not accurately measure innate ability and that environmental influences from disadvantaged homes might affect scores. He concluded that the IQ measures and the tracking decisions were flawed, and ruled against the use of IQ measures for tracking purposes. The case was more broad than simply objecting to tracking procedures, as demonstrated in the following video

  • Larry P. vs. Wilson Riles: After thousands of African-American children were placed into special education programs in California in the 70s and 80s based upon standardized tests of intelligence, and the assumption that these tests were valid measures of their intelligence, the judge prohibiting them from using about 20 tests on African American children as it was determined that all of these measures improperly categorized these children as being in the mentally retarded range when they were not.

    The judge also labeled IQ tests racially and culturally biased.. not validated for purpose of consigning black children into educationally dead-end, isolated, stigmatizing classes, and prohibited individual IQ testing with black children.

  • Parents in Action on Special Education v. Hannon: In a class-action suit African-American students in Illinois believed they were overrepresented in special education classes (MR). As in Larry P, the plaintiffs argued that IQ tests were biased and African-American students were improperly classified and placed in the MR classes. However, in contrast to Larry P., the judge did not rule that IQ tests were racially or culturally biased. He noted that individually administered intelligence tests were not racially biased, and when used with other procedures did not discriminate against African-American students

  • Crawford et al, v. Honig et al. This case challenged the Larry P. ruling banning the use of IQ tests for African-American children and had resulted in three African-American children being allowed to take IQ tests because their parents wish to have them do so. (Crawford cannot get IQ testing of mulatto child, sues for equal protection. Larry P is reversed by original judge.)

  • Marshall v. Georgia: Rejected the notion that tracking, and using test to do so, is bad for children even if it leads to statistical disparities in placements. As a disproportionately large number of African-American students were placed in lower achievement groups, they felt that minority groups were improperly tracked, and a disproportionately large number were placed in the MR special education classes. The judge ruled in the favor of the defendants (school districts), citing that grouping based on achievement was acceptable and that benefits in achievement due to grouping was demonstrated by the schools.

  • Golden Rule Insurance et al v. Washburn et al: ETS agrees to remove all licensing items upon which blacks and whites differ by more than 15%.

  • 1991 Civil Rights Act: It shall be unlawful employment practice...in connection with... employment or selection...to adjust scores, use different cutoff scores, or otherwise alter the results of employment related tests on the basis of race, color, religion, sex, or national origin.

Example of Use of Effort Testing