此处，“John Doe investigation”中的“John Doe”不再指代不知姓名的人，而是特指一种法律程序。

BALLOTPEDIA对“John Doe investigation”的解释如下：

“A John Doe investigation is a legal proceeding in the state of Wisconsin that is governed by Wisconsin Statute section 968.26. John Doe investigations are initiated by a judge and allow law enforcement the ability to subpoena witnesses while simultaneously preventing them from legally discussing the investigation in public. Circuit judges oversee the investigations. A John Doe proceeding may be used to investigate "any conduct that is prohibited by state law and punishable by fine or imprisonment or both," with no limitation on the type of crime being investigated. A John Doe investigation is similar to a grand jury investigation, however in the case of the John Doe, there is no jury of peers but rather the case is strictly overseen by the judge.”

John Doe investigation是美国威斯康星州的一项法律程序，与一般刑事诉讼程序不同，因为就一般刑事诉讼程序而言，只要有可成立的理由表明某人触犯了法律即可提起诉讼，但是这项法律程序是帮助执法机构获得必要证据以确定确实存在可成立的理由，目的是让法官根据证人证言判断是否发生犯罪，是否提交诉状，同时也是保护无辜的公民免遭无意义的刑事诉讼。因此，在这项法律程序中，执法机构拥有下列权力：传讯证人，获得经宣誓的证人证言，对证人给予不因其提供的证言而受刑事追诉的豁免，强制不愿作证的证人作证（Wisconsin Statute Section 968.26 (3)(d)规定：“A court, on the motion of a district attorney, may compel a person to testify or produce evidence under s. 972.08 (1). The person is immune from prosecution as provided in s. 972.08 (1), subject to the restrictions under s. 972.085.”）。整个程序由巡回法官监督。

大多数情况下，John Doe investigation程序的启动始于地区检察官向有管辖权的法官提交刑事控告书，说明某一犯罪行为已经发生，然后由法官对地区检察官确认的证人进行传讯和询问（Wisconsin Statute Section 968.26 (1m)规定：“If a district attorney requests a judge to convene a proceeding to determine whether a crime has been committed in the court's jurisdiction, the judge shall convene a proceeding described under sub. (3) and shall subpoena and examine any witnesses the district attorney identifies.”）。但是，非地区检察官的公民也可以启动该程序，若其有理由相信已经发生某一犯罪行为，其向有管辖权的法官提交刑事指控书，法官再将刑事指控书送交地区检察官，若检察官拒绝提出控告，法官可复核执法机构出具的相关调查报告并决定是否启动该程序（Wisconsin Statute Section 968.26 (2)(am)规定：“If a person who is not a district attorney complains to a judge that he or she has reason to believe that a crime has been committed within the judge's jurisdiction, the judge shall refer the complaint to the district attorney or, if the complaint may relate to the conduct of the district attorney, to another prosecutor under s. 978.045.”同时，(2)(b)规定：“If a district attorney receives a referral under par. (am), the district attorney shall, within 90 days of receiving the referral, issue charges or refuse to issue charges. If the district attorney refuses to issue charges, the district attorney shall forward to the judge in whose jurisdiction the crime has allegedly been committed all law enforcement investigative reports on the matter that are in the custody of the district attorney, his or her records and case files on the matter, and a written explanation why he or she refused to issue charges. The judge may require a law enforcement agency to provide to him or her any investigative reports that the law enforcement agency has on the matter. The judge shall convene a proceeding as described under sub. (3) if he or she determines that a proceeding is necessary to determine if a crime has been committed. When determining if a proceeding is necessary, the judge may consider the law enforcement investigative reports, the records and case files of the district attorney, and any other written records that the judge finds relevant.”）。

通常情况下，Wisconsin法庭审理程序采用公开聆讯方式进行，但是，在John Doe investigation程序下，法官有权决定是否公开询问。法官会在地区检察官出示充分理由的情况下签发保密令，一般来说，保密令涉及提出的问题、问题回答、庭审记录、出示的证据等。（有关保密令的规定，可参见Wisconsin Statute Section 968.26 (4)(a)-(d)）

至于John Doe investigation程序适用于哪种犯罪行为，Wisconsin Statute Section 968.26 (5)(b)作了如下规定：“A proceeding may not investigate a crime that was not part of the original request under sub. (1m) or complaint under sub. (2) (a), whichever is appropriate, unless a majority of judicial administrative district chief judges find good cause to add specified crimes and the identification of the vote of each judge is available to the public. An unlimited number of specified crimes may be added but, for each addition of a specified crime, a majority of judicial administrative district chief judges must find good cause and the identification of the vote of each judge must be available to the public.”也就是说，这项程序适用的犯罪行为应该是(1m)项下地区检察官提交的刑事控告书中的犯罪行为，或是(2)(a)项下非地区检察官的公民提交的刑事控告书中的犯罪行为，但也有例外情况，若大多数司法行政地区首席法官认为有充分理由加入特定犯罪行为，且向公众告知法官就这一行为进行的投票情况，则该特定犯罪行为可适用于John Doe investigation程序，且对新添加犯罪行为的数量不设限。