精神失常抗辩及其刑事证明——以美国法为视角

心智健全推定卸除了控方对被告人心智健全的证明责任，将争点形成责任交由辩方承担。而精神失常在美国刑事法中属于积极抗辩事由，根据联邦和多数州的司法实践，由辩方承担提出初步的举证责任，并承担“清晰、信服”程度的说服责任。相较之下，我国目前刑事实体法的建构与刑事证明之间没有明确的衔接，以至于刑事证明的功能无法有效实现。司法精神病鉴定是目前查实被告人是否精神失常的主要手段，但启动权主要其中在公安司法机关手中，辩方权利受到较大限制，而对鉴定人以及鉴定证据亦缺乏体系性的证据审用规则。司法精神病鉴定应当纳入刑事证明的轨道，辩方如欲推翻心智健全推定，应提出相应证据，继而说服责任的分配要区分辨方证明主张：该鉴定意见是对控方对犯罪主观方面要素证明的反驳，还是主张责任阻却。前者由控方证明到排除合理怀疑的程度，而后者则由辩方证明到清晰、信服的程度。在此证明原理的基础上，鉴定人有义务出庭对鉴定意见进行口头陈述或展示，并接受对造的质证。鉴定意见的证据能力则由法庭依法判断，其证明力则由法庭自由评价。

Insanity defense and its burden of proof in American criminal justice system

The presumption of sanity waives the prosecution＇s burden to prove the defendant＇s sanity, and the burden of proof shifts to the defendant to make it a legal issue in court. Insanity is taken as one of the affirmative defenses that the defendant has to take the burden of initial production and the burden of ＂clear and convincing＂ persuasion most of the time according to U.S. federal and most states judicial practices. On the contrary, in current laws of China, the prosecution has to prove all the elements to construct an offense including sanity. The defendant has little opportunity to test liability and credibility of the prosecution＇s expert witness, as the defendant does not have the right to call for its own expert witness or the right to cross-examine adversary witness. Testimony concerning insanity is allocated high evidential value by the judge. In conclusion, sanity or insanity in China＇s statutes and practice has not yet been taken as one of the issues that need to be proven by the defendant just like American insanity defense. If it is so, when it comes to which the defendant has to take the burden of persuasion, the evidential standard shall be lower than incriminating one （e.g., beyond reasonable doubt）. Clear and convincing evidence standard might be the appropriate one.