OBJECTIVES Firearms experts traditionally have testified that a weapon leaves "unique" toolmarks, so bullets or cartridge casings can be visually examined and conclusively matched to a particular firearm. Recently, due to scientific critiques, Department of Justice policy, and judges' rulings, firearms experts have tempered their conclusions. In two experiments, we tested whether this ostensibly more cautious language has its intended effect on jurors (Experiment 1), and whether cross-examination impacts jurors' perception of firearm testimony (Experiment 2). HYPOTHESES Four hypotheses were tested. First, jurors will accord significant weight to firearm testimony that declares a "match" compared to testimony that does not (Experiments 1 and 2). Second, variations to "match" language will not affect guilty verdicts (Experiment 1). Third, only the most cautious language ("cannot exclude the gun") would lower guilty verdicts (Experiment 1). Fourth, cross-examination will reduce guilty verdicts depending on specific language used (Experiment 2). METHOD In two preregistered, high-powered experiments with 200 mock jurors per cell, participants recruited from Qualtrics Panels were presented with a criminal case containing firearms evidence, which varied the wording of the examiner's conclusion and whether cross-examination was present. These variations include conclusion language used by practitioners, language advised by government organizations, and language required by judges in several cases. Participants gave a verdict, rated the evidence and expert in all conditions. RESULTS Guilty verdicts significantly increased when a match was declared compared to when a match was not declared. Variation in conclusion language did not affect guilty verdicts nor did it affect jurors' estimates of the likelihood the defendant's gun fired the bullet recovered at the crime scene. In contrast, however, a more cautious conclusion that an examiner "cannot exclude the defendant's gun" did significantly reduce guilty verdicts and likelihood estimates alike. The presence of cross-examination did not affect these findings. CONCLUSION Apart from the most limited language ("cannot exclude the defendant's gun"), judicial intervention to limit firearms conclusion language is not likely to produce its intended effect. Moreover, cross-examination does not appear to affect perceptions or individual juror verdicts. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

中文翻译：

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模拟陪审员对枪支审查员证词的评估。

目标传统上，枪支专家已证明武器留下了“独特的”工具标记，因此可以目视检查子弹或子弹壳并最终与特定枪支匹配。最近，由于科学批评，司法部的政策以及法官的裁定，枪支专家对他们的结论进行了调整。在两个实验中，我们测试了这种表面上更为谨慎的语言是否对陪审员产生了预期的影响（实验1），以及交叉盘问是否会影响陪审员对枪支证言的理解（实验2）。假设检验了四个假设。首先，陪审员将对宣告“相称”的枪支证词给予与未作证的证词相当的重视（实验1和2）。第二，“匹配”的变体 语言不会影响有罪判决（实验1）。第三，只有最谨慎的语言（“不能排除枪支”）才会降低有罪判决（实验1）。第四，根据所使用的特定语言，盘问将减少有罪判决（实验2）。方法在两个预先注册的功能强大的实验中，每个单元200个模拟陪审员，向从Qualtrics小组招募的参与者展示了一个包含枪支证据的刑事案件，这改变了审查员结论的措辞以及是否存在盘问。这些变化包括从业人员使用的结论语言，政府组织建议的语言以及在某些情况下法官要求的语言。参与者给出了一个结论，在所有情况下都对证据和专家进行了评级。结果与没有宣布比赛时相比，宣布比赛时有罪判决显着增加。结论语言的变化既不会影响有罪判决，也不会影响陪审员的估计，即被告人的枪射击了犯罪现场回收的子弹的可能性。但是，相比之下，更为审慎的结论是，审查员“不能排除被告的枪支”确实大大减少了有罪判决和可能性估计。盘问的存在并未影响这些发现。结论除了使用最受限制的语言（“不能排除被告的枪支”）之外，限制枪支结论语言的司法干预也不太可能产生预期的效果。而且，盘问似乎不会影响看法或个别陪审员的裁决。（PsycInfo数据库记录（c）2020 APA，保留所有权利）。