On Fox News last night, between the commercials for self-lubricating catheters and class-action lawsuits over defective hip replacements, you may have seen Tucker Carlson ranting about the release of "hundreds of violent criminals" onto the streets of America.

In a segment on his show, Carlson said that a source within the Trump administration had provided his show with exclusive data on crimes committed by the roughly 3,100 federal inmates who were released earlier this month under the FIRST STEP Act, a criminal justice reform bill passed by Congress last December.

Tucker Carlson blasting the First Step Act tonight. The bill was sold as a way to give a second chance to nonviolent offenders. Instead "that law has allowed hundreds of violent criminals & sexual predators back onto the streets." pic.twitter.com/9ZR0LytYtl — The Columbia Bugle ???????? (@ColumbiaBugle) July 23, 2019

"So far this year, more than 2,000 federal prisoners were put on the nation's streets thanks to the FIRST STEP Act," Carlson begins. "You might remember that law. It was sold to lawmakers and the rest of us a way to ease overcrowded prisons and give a second chance to nonviolent offenders. That's not what it's turned into."

Carlson continues:

In fact, that law has allowed hundreds of violent criminals and sexual predators back on the street. An administration official provided this show exclusively with data on what crimes were committed by the felons being released under the FIRST STEP Act. Turns out most of them were not in jail for smoking a joint 30 years ago. Instead, of the roughly 2,200 inmates who've been set free so far, 496 of them were in prison on charges related to weapons or explosives. Huh. Two hundred and thirty nine had committed sex offenses such as rape and sexual assault, 106 committed armed robbery, and 59 had committed aggravated assault or murder. That's not what we were promised.

This is the part where gentle viewers are supposed to clutch their hearts and say, "My God, what's happening to my country?"

The actual story is much less alarming.

All of the inmates Tucker is referencing had their release dates moved up because the FIRST STEP Act forced the federal Bureau of Prisons (BOP) to change the way it calculates the amount of "good time" credits inmates can earn through good behavior to shave days off their sentence.

You see, in the federal prison system, inmates were supposed to be eligible for 54 days of good time credits a year. Keeping a clean disciplinary record is one of the only ways federal inmates can reduce their sentences, since there is no parole in the federal system.

In practice, however, they could only accrue 47 days a year, thanks to the absurdly complicated way BOP calculated the credits. (If you're really a glutton for punishment, you can read a long summary of BOP's good time credit formula in a 2010 Supreme Court ruling upholding it, which includes an appendix entry about the algebra equations involved.)

For a federal inmate doing 10 years of hard time, that meant losing 70 days of potential credit toward an earlier release.

The FIRST STEP included a provision to ensure that inmates can now actually receive 54 days of good time credit a year, and it required BOP to retroactively recalculate credits for current inmates and adjust their release dates accordingly. Because of a drafting error in the bill, that provision didn't go into effect until July 19.

Lawmakers and advocacy groups who supported the FIRST STEP Act say the provision was simply a fix to clarify Congress' original legislative intent. In other words, these inmates were getting out exactly when they should have under the spirit of the law.

"Every single office we met with during the course of the FIRST STEP Act was told about that provision," says Jason Pye, vice president of legislative affairs at FreedomWorks, a conservative group that supported the legislation. "Virtually every communication we sent to the Hill about the FIRST STEP Act at least mentioned this provision, explained what it was, and why it was included in the bill. It was a feature of the FIRST STEP Act, and it was included to fix a misapplication of law by the Bureau of Prisons, which had calculated the 54 days of good time credit that could be earned by a prisoner to mean 47 days."

All of the inmates Carlson is fulminating about were going to be released anyway—and sooner rather than later. Most were released from halfway houses or home confinement where they were finishing out their sentences. And they're all still subject to three to five years of supervised release.

Naturally, Carlson's millions of viewers were left without this information.

Does Carlson think these inmates are at a higher risk of committing new crimes because they were released a few months earlier than they would have previously been? Or is he simply outraged that they were released at all? If it's the latter, his beef goes far beyond the modest FIRST STEP Act. More than 10,000 inmates are released from U.S. state and federal prisons every week, according to the Justice Department, for all manner of crimes. More than 95 percent of all state prisoners will eventually be released.

It's unclear exactly what Carlson wants us to be upset about—only that he wants us to be upset.