For the nation’s armchair prosecutors, these are prosperous times. Each day seems to bring a brand-new possibility or development in a well-publicized criminal investigation, as well as the chance to predict if a prominent public figure will end up behind bars. We tend to focus on Donald Trump these days, but the current president’s son, Hunter Biden, is also the subject of a federal criminal investigation, which has raised similar concerns about how the inquiry will be handled.

However, a large portion of this analysis has depended on a mechanistic explanation of how federal prosecutors work in difficult cases, presuming that if there is enough evidence of a crime, it will or at the very least should be prosecuted. That is, at best, inaccurate, and at worst, incomplete. The end result has been a widespread oversimplification of the issues that Attorney General Merrick Garland and the prosecutors working on these investigations will need to address — and the real possibility that many people will be perplexed or disappointed, in one way or another, if their preferred target is ultimately not indicted.

It is important to step back and comprehend the criteria that the Justice Department is required to use when deciding whether to seek an indictment against someone. The government has a set of rules that govern these “charging choices,” but they give prosecutors latitude in deciding whether to charge someone criminally. In the Trump and Biden instances, this latitude may be of the utmost importance.

According to Justice Department regulation, this internal charging examination has two main components: a legal component and a prudential component, both of which must be satisfied.

Prosecutors must first decide if they can genuinely convict the potential offender at a trial. According to Justice Department policy, prosecutors “shall start or propose federal prosecution” if they feel that the “admissible evidence” will “probably” result in a conviction at trial. Or, to put it another way, they must have faith that they can, despite potential trial defences, which prosecutors also consider when making their decision, actually persuade a jury to unanimously find that the defendant committed each element of the pertinent criminal offence beyond a reasonable doubt. A thorough examination of the admissible evidence under particular federal criminal statutes and the case law governing those statutes is the basis of this effort.

Second, prosecutors must take into account a variety of discretionary criteria in addition to the legal analysis, some of which may militate against charging either Trump or Hunter Biden. Prosecutors must specifically take into account “(1) the prosecution would serve no substantial federal interest; (2) the person is subject to effective prosecution in another jurisdiction; or (3) there exists an acceptable non-criminal alternative to prosecution.” Nine separate subsidiary considerations are listed by the Justice Department as potential factors that could support or contradict a determination that filing charges would be in the “substantial federal interest.” The offense’s seriousness, the prosecution’s ability to deter future crimes, the accused’s “culpability in connection with the offence,” his criminal record, his “personal circumstances,” and the “probable sentence or other consequences if the person is convicted” are all on the list, which is not exhaustive.