If you’re looking for a good example of the law of unintended consequences, search no further than the actions of so-called “progressive prosecutors.”

In the name of reforming the criminal justice system, they end up making conditions even worse.

“I think the best way to define a progressive prosecutor is someone who uses his or her office to pursue reforms primarily, as opposed to the enforcement of the law.” That’s the assessment from Rafael Mangual, senior fellow and head of research for the Manhattan Institute’s Policing and Public Safety Initiative. Mangual offered that definition during a March 21 online presentation for the John Locke Foundation.

“Those reforms move in a particular direction,” Mangual added. “They’re aimed at decriminalization, decarceration, and de-policing. In other words, they’re reforms aimed at lowering the transaction costs of criminal behavior while raising the transaction costs of criminal enforcement.”

Progressive prosecution developed in response to two perceived problems, Mangual argues. First, police needed to face greater accountability for their actions. Second, standard forms of prosecution helped lead to “mass incarceration,” according to the progressives.

When a highly publicized 2014 police shooting in Ferguson, Missouri, led to no criminal charges against the shooting officer, the local district attorney was ousted in a primary election. “That was one of the first dominoes to really fall,” Mangual said.

“You started to see a realization around the country that this was actually a viable avenue for broader reforms that aimed beyond just police accountability,” he added.

Spurred on by the Ferguson case, other police shootings, and Fordham University law professor John Pfaff’s anti-incarceration book “Locked In,” would-be reformers started a movement “that has just expanded in scope to an enormous degree,” Mangual said.

“The term ‘progressive prosecutor’ was probably unfamiliar to most Americans just 10 years ago,” he said. “Now we’re at a point in which nearly 50 million Americans are living in jurisdictions with self-described progressive prosecutors.”

Those prosecutors tend to share some basic characteristics, Mangual said. They establish policies of not prosecuting certain crimes. They regularly downgrade charges to lesser offenses before starting plea negotiations. They de-emphasize pretrial and post-conviction time behind bars. They focus instead on diversion programs, along with more probation and parole.

These changes face two basic criticisms from Mangual.

“The progressive prosecutor movement is really anti-democratic in nature,” he said, explaining his first major complaint. “What the reformers figured out was that rather than spend a lot of money on lobbying local officials and trying to pursue legislative reform, they could actually dump much less money into a less visible but really consequential race.”

Winning an election for district attorney could have major consequences, Mangual said. “You then have one person who essentially gets to unilaterally abrogate bodies of duly enacted legislation within that jurisdiction by choosing not to pursue cases that fall under those crimes that are disfavored.”

Mangual’s second complaint focuses on the “public safety implications” of the progressive prosecutor movement. “When you systematically lower the transaction costs of criminal behavior and raise the transaction costs of criminal enforcement, what you’re doing is encouraging the sorts of behaviors that I think everyone wants to see less of.”

“If it becomes less costly to commit more crime, you’re going to see more crime.”

Progressive prosecutors’ policies reduce the deterrence factor of law enforcement. They also raise an “incapacitation question,” Mangual said.

“If you look at cities across the country, what you’ll see is that a lot of the most serious crimes are driven by repeat customers, repeat offenders, people who have lengthy criminal histories,” he said. Often, these offenders have active sentences as they commit new crimes.

From 1990 to 2002, 36% of all violent felony offenders were out on the streets on probation, parole, or pretrial release at the time of their latest offense. “In the city of Chicago, for example, which has been struggling with elevated levels of violence for quite some time, the average homicide or shooting suspect has 12 prior arrests,” Mangual said.

“In New York City, we saw a nearly 27% increase in the percentage of violent felony arrests constituted by people with open cases after our bail reform, which a lot of progressive prosecutors are pursuing on their own by not pursuing pretrial detention in a lot of cases,” he added.

These numbers lead Mangual to a conclusion. “Police seem to be doing a relatively good job of focusing their resources on the people driving serious crime,” he said. “The public safety benefits of that kind of enterprise get diminished if you don’t have those efforts backed up by prosecution.”

The most likely outcome: More repeat offenders will have more opportunities to commit crime. “Of course, that crime is not going to be evenly distributed across any jurisdiction,” Mangual warned. “It’s going to be highly concentrated in the most vulnerable neighborhoods.”

It’s an unintended negative consequence of the push for “progressive” reform.

Mitch Kokai is senior political analyst for the John Locke Foundation.