Invalid Forensic Science Testimony and Wrongful Convictions

This is the first study to explore the forensic science testimony by prosecution experts in the trials of innocent persons, all convicted of serious crimes, who were later exonerated by post-conviction DNA testing. Trial transcripts were sought for all 156 exonerees identified as having trial testimony by forensic analysts, of which 137 were located and reviewed. These trials most commonly included testimony concerning serological analysis and microscopic hair comparison, but some included bite mark, shoe print, soil, fiber, and fingerprint comparisons, and several included DNA testing. This study found that in the bulk of these trials of innocent defendants - 82 cases or 60% - forensic analysts called by the prosecution provided invalid testimony at trial - that is, testimony with conclusions misstating empirical data or wholly unsupported by empirical data. This was not the testimony of a mere handful of analysts: this set of trials included invalid testimony by 72 forensic analysts called by the prosecution and employed by 52 laboratories, practices, or hospitals from 25 states. Unfortunately, the adversarial process largely failed to police this invalid testimony. Defense counsel rarely cross-examined analysts concerning invalid testimony and rarely obtained experts of their own. In the few cases in which invalid forensic science was challenged, judges seldom provided relief. This evidence supports efforts to create scientific oversight mechanisms for reviewing forensic testimony and to develop clear scientific standards for written reports and testimony. The scientific community can through an official government entity promulgate standards to ensure the valid presentation of forensic science in criminal cases and thus the integrity and fairness of the criminal process

Invalid Forensic Science Testimony and Wrongful Convictions

This is the first study to explore the forensic science testimony by prosecution experts in the trials of innocent persons, all convicted of serious crimes, who were later exonerated by post-conviction DNA testing. Trial transcripts were sought for all 156 exonerees identified as having trial testimony by forensic analysts, of which 137 were located and reviewed. These trials most commonly included testimony concerning serological analysis and microscopic hair comparison, but some included bite mark, shoe print, soil, fiber, and fingerprint comparisons, and several included DNA testing. This study found that in the bulk of these trials of innocent defendants - 82 cases or 60% - forensic analysts called by the prosecution provided invalid testimony at trial - that is, testimony with conclusions misstating empirical data or wholly unsupported by empirical data. This was not the testimony of a mere handful of analysts: this set of trials included invalid testimony by 72 forensic analysts called by the prosecution and employed by 52 laboratories, practices, or hospitals from 25 states. Unfortunately, the adversarial process largely failed to police this invalid testimony. Defense counsel rarely cross-examined analysts concerning invalid testimony and rarely obtained experts of their own. In the few cases in which invalid forensic science was challenged, judges seldom provided relief. This evidence supports efforts to create scientific oversight mechanisms for reviewing forensic testimony and to develop clear scientific standards for written reports and testimony. The scientific community can through an official government entity promulgate standards to ensure the valid presentation of forensic science in criminal cases and thus the integrity and fairness of the criminal process

The Reliability of Eyewitness Testimony

As perhaps the single most effective method of proving the elements of a crime, eyewitness testimony has been vital to the trial process for centuries. However, the reliability of eyewitness testimony has recently come into question with the work of organizations such as The Innocence Project, which works to exonerate the wrongfully convicted. This thesis examines previous experiments concerning eyewitness testimony as well as court cases in which eyewitnesses provided vital evidence in order to determine the reliability of eyewitness testimony as well as to determine mitigating or exacerbating factors contributing to a lack of reliability

The prediction of future behavior: The empty promises of expert clinical and actuarial testimony

Testimony about the future dangerousness of a person has become a central staple of many judicial processes. In settings such as bail, sentencing, and parole decisions, in rulings about the civil confinement of the mentally ill, and in custody decisions in a context of domestic violence, the assessment of a person’s propensity towards physical or sexual violence is regarded as a deciding factor. These assessments can be based on two forms of expert testimony: actuarial or clinical. The purpose of this paper is to examine the scientific and epistemological basis of both methods of prediction or risk assessment. My analysis will reveal that this kind of expert testimony is scientifically baseless. The problems I will discuss will generate a dilemma for factfinders: on the one hand, given the weak predictive abilities of the branches of science involved, they should not admit expert clinical or actuarial testimony as evidence; on the other hand, there is a very strong tradition and a vast jurisprudence that supports the continued use of this kind of expert testimony. It is a clear case of the not so uncommon conflict between science and legal tradition

Sources of Unreliable Testimony from Children

We distilled research findings on sources of unreliable testimony from children into four principles that capture how the field of forensic developmental psychology conceptualizes this topic. The studies selected to illustrate these principles address three major questions: (a) how do young children perform in eyewitness studies, (b) why are some children less accurate than others, and (c) what phenomena generate unreliable testimony? Throughout our research, our focus is on factors other than lying that produce inaccurate or seemingly inconsistent autobiographical reports.Collectively, this research has shown that (a) children’s eyewitness accuracy is highly dependent on context, (b) neurological immaturity makes children vulnerable to errors under some circumstances, and (c) some children are more swayed by external influences than others. Finally, the diversity of factors that can influence the reliability of children’s testimony dictates that (d) analyzing children’s testimony as if they were adults (i.e., with adult abilities, sensibilities, and motivations) will lead to frequent misunderstandings. It takes considerable knowledge of development—including information about developmental psycholinguistics, memory development, and the gradual emergence of cognitive control—to work with child witnesses and to analyze cases as there are many sources of unreliable testimony

David Hume's Reductionist Epistemology of Testimony

David Hume advances a reductionist epistemology of testimony: testimonial beliefs are justified on the basis of beliefs formed from other sources. This reduction, however, has been misunderstood. Testimonial beliefs are not justified in a manner identical to ordinary empirical beliefs; it is true, they are justified by observation of the conjunction between testimony and its truth, but the nature of the conjunctions has been misunderstood. The observation of these conjunctions provides us with our knowledge of human nature and it is this knowledge which justifies our testimonial beliefs. Hume gives a naturalistic rather than a sceptical account of testimony

Assertion and Testimony

[The version of this paper published by Oxford online in 2019 was not copy-edited and has some sense-obscuring typos. I have posted a corrected (but not the final published) version on this site. The version published in print in 2020 has these corrections.] Which is more fundamental, assertion or testimony? Should we understand assertion as basic, treating testimony as what you get when you add an interpersonal addressee? Or should we understand testimony as basic, treating mere assertion -- assertion without testimony -- as what you get when you subtract that interpersonal relation? In this chapter, I’ll argue for the subtractive approach and for the more general thesis that its treatment of the interpersonal element in assertion makes understanding that interpersonal element the key to understanding how assertion expresses belief. My theory of belief-expression in assertion treats it as internalizing the transmission of belief in testimony. How we understand that internalizing move depends on how we conceptualize the interpersonal element in testimony. Since what I’ll call the Command Model does not give us the conceptual resources to make this move, we should adopt an alternative that I’ll call the Custodial Model, on which a testifier aims not to convince her addressee but to reason with him – to give him reasons to believe what she tells him grounded in her trustworthiness in thus attempting to influence him. The subtractive approach to assertion thus rests on a key distinction between the aims of reasoning and persuasion

Evaluating Future Dangerousness and Need for Treatment: The Roles of Expert Testimony, Attributional Complexity, and Victim Type

In the current study, we explored the effect of risk-assessment testimony, attributional complexity, and victim type on participants’ perceptions of the dangerousness of a sexually violent person and his need for treatment. Participants read details of a hypothetical sexual assault of a female minor and of an adult. Expert testimony of his risk assessment consisted of clinical opinion versus structured-clinical judgment (SCJ) versus actuarial assessment. Participants perceived clinical-opinion and SCJ testimony as equally influential when forming judgments of future dangerousness. In the context of treatment, however, participants relied on actuarial testimony when judging potential for risk. In addition, attributional complexity (AC) moderated perceptions of sexual risk. Overall, results point to the need for continued refinement of assessment techniques when determining dangerousness and need for treatment

Intellectualism and Testimony

Knowledge-how often appears to be more difficult to transmit by testimony than knowledge-that and knowledge-wh. Some philosophers have argued that this difference provides us with an important objection to intellectualism—the view that knowledge-how is a species of knowledge-that. This article defends intellectualism against these testimony-based objections

Epistemic internalism and testimonial justification

ABSTRACTAccording to epistemic internalists, facts about justification supervene upon one's internal reasons for believing certain propositions. Epistemic externalists, on the other hand, deny this. More specifically, externalists think that the supervenience base of justification isn't exhausted by one's internal reasons for believing certain propositions. In the last decade, the internalism–externalism debate has made its mark on the epistemology of testimony. The proponent of internalism about the epistemology of testimony claims that a hearer's testimonial justification for believing that p supervenes upon his internal reasons for thinking that the speaker's testimony that p is true. Recently, however, several objections have been raised against this view. In this paper, I present an argument providing intuitive support for internalism about the epistemology of testimony. Moreover, I also defend the argument against three recent objections offered by Stephen Wright in a couple of recent papers. The upshot of my discussion is that external conditions do make an epistemic difference when it comes to our testimonial beliefs, but that they cannot make any difference with respect to their justificatory status – i.e., they are justificationally irrelevant