DNA Examiners: Judgment and Influence

DNA分析被广泛认为可以在法律案件中提供客观和准确的证据。但是，像其他法医方法一样，DNA分析需要人类的判断。这种判断可能会受到非法医背景信息的影响。一个重要但尚未研究的问题是，DNA检查员关于如何检测物体DNA的决定是否取决于背景线索，如警方调查人员的评论。如果是这样的话，这就引发了这样的问题：(A)这种线索是否会影响检验员是否在物体上发现DNA，(B)检验员如何应对与他们所做测试选择有关的挑战，以及(C)陪审员在此类挑战之后如何权衡DNA证据。本研究包括两个对照实验研究。在研究1中，100名经验丰富的DNA检验员将从一个模拟的刑事案件中收到材料，在这个案件中，他们对DNA证据可能存在于物体上的位置的预期是通过上下文线索来操纵的。然后，检查人员将进行DNA分析并得出结论。下一步，考官将对挑战他们考试决定和结论的类似交叉考试的问题做出回应。研究二考察了模拟陪审员对案件的判决和决定如何受到(A)DNA审查员交叉询问中提出的论点的复杂性以及(B)审查员对这些论点的反应的影响。这项研究对刑事司法系统、法医学实践和心理学理论的发展具有重要意义。刑事司法系统受益于识别并纠正可能干扰法医决策的因素。这些改进可能会被纳入法医科学培训计划和方案，有助于定罪和释放无辜者。这项研究还通过洞察认知和动机偏见如何以及何时在复杂的、多阶段的多人决策任务中发挥作用，促进了心理学理论的发展。

DNA analysis is widely believed to offer objective and accurate evidence in legal cases. But, like other forensic methods, DNA analysis requires human judgment. Such judgment may be influenced by non-forensic contextual information. An important and as yet unstudied issue is whether a DNA examiner's decision about how to test an object for DNA depends on contextual cues such as comments made by police investigators. If so, this raises questions about (a) whether such cues can affect whether an examiner finds DNA on an object, (b) how examiners respond to challenges pertaining to the testing choices they make, and (c) how jurors weigh DNA evidence following such challenges. This research includes two controlled experimental studies. In Study 1, one hundred experienced DNA examiners will receive materials from a simulated criminal case in which their expectations about where DNA evidence likely exists on an object is manipulated via contextual cues. The examiners will then perform a DNA analysis and provide conclusions. Next, the examiners' will respond to cross-exam-like questions that challenge their testing decisions and conclusions. Study 2 examines how mock jurors' judgments and decisions about a case are affected by (a) the complexity of arguments raised on the DNA examiner's cross-exam, and (b) the examiner's response to those arguments.This research has significant implications for the criminal justice system, for the practice of forensic science, and for the advancement of psychological theory. The criminal justice system benefits from identifying, and then correcting for, factors that can interfere with forensic decision-making. These improvements, which may find their way into forensic science training programs and protocols, can help convict the guilty and free the innocent. This research also advances psychological theory by providing insight into how and when cognitive and motivational biases operate in a complex, multi-stage, multi-person decision task.