Last September, Michelino Sunseri, a bartender and sponsored professional mountain runner, broke the Grand Teton speed record. Unhappy with how Sunseri set his record, the National Park Service requested that the website that maintains the records refuse to recognize it. As if that wasn’t enough, the Department of Justice decided to prosecute Sunseri for running on a closed trail.

When Sunseri set his sights on achieving a record in Grand Teton National Park, he had no reason to believe he was committing a crime. Yet, whether in our pristine national parks or on the high seas, federal prosecutors have found a way to turn ordinary conduct into criminal activity — terrorizing well-meaning people in the process.

Record holders before Sunseri had used the same trail, and tour guides who charge hefty sums frequently lead hikers up the same route. Only two tiny and ambiguous signs inform the public that the trail is off-limits. So, it makes sense that this conduct never elicited the attention of federal prosecutors — up until Sunseri, that is.

Assistant U.S. Attorney Ariel Calmes sought to make an example of Sunseri. The prosecutor charged him with violating a federal regulatory misdemeanor — which was never passed by Congress but carries up to six months in jail — for “leaving a trail or walkway to shortcut between portions of the same trail or walkway, or to shortcut to an adjacent trail or walkway in violation of designated restrictions.”

Upon learning of the charges against him, Sunseri sought to placate the prosecutor by volunteering to improve signage and trail conditions. Having none of it, the government repeatedly rejected Sunseri’s offers. The only offer prosecutors extended was for Sunseri to plead guilty and face a $5,000 fine and a five-year ban from Grand Teton National Park — forcing him and his three Siberian Huskies from their home and jeopardizing his North Face sponsorship.

Sunseri’s prosecution is notable for another reason. Charged with an offense that carries a maximum of six months in jail, Sunseri is being denied his constitutional right to a jury trial thanks to an arbitrary carveout created by the Supreme Court known as the “Petty Offense Exception.” The Constitution’s text explicitly commands that the trial of “all” federal crimes be by jury, and it underscores that command by repeating in the Sixth Amendment that “in all criminal prosecutions” the defendant has the right to a public trial by an impartial jury. The Cato Institute recently filed an amicus brief in a similar case asking the Supreme Court to abolish the “Petty Offense Exception,” arguing that it lacks any historical foundation and is wholly incompatible with the original public meaning of the Constitution.

In cases like Sunseri’s, the right to a jury trial is of particular importance. Historically, jurors weren’t relegated to the mere fact-finding role they are today. Founding-era jurors were tasked with preventing injustice. Criminal jurors had a civic duty to assess the wisdom, legitimacy and fairness of a given prosecution, and they had the power to acquit against the evidence to prevent injustice.

It is doubtful that a jury fully cognizant of its historical powers and duties would convict Sunseri. It is certain that he will not have the benefit of such a jury because the system makes a point of curating the jury pool to eliminate anyone who expresses sympathy toward acquitting against the evidence.

The core function of our criminal justice system ought to be protecting the public from individuals whose conduct threatens the very fabric of civil society. The criminal justice system was intended to be a tool of last resort — as Justice Neil Gorsuch notes in his recent book, “criminal laws are not the solution to every problem.”

A criminal justice system must be perceived by the public as legitimate to be effective. Prosecuting people like Michelino Sunseri, whose conduct is just barely, if at all, wrongful in the sense that it presents genuine harm to others, erodes the rule of law and undermines public trust.