Some people can learn only through experience. All the factual presentations and logical arguments in the world do nothing for them. Disgraced former New York Police Commissioner Bernie Kerik is one of those people. But better to learn by experience than not at all.

The onetime hard-as-nails lawman now crusades to reform the U.S. justice system.

As a law-and-order tough guy who sat at the right hand of New York’s iron-fisted Mayor Rudy Giuliani, Kerik presided over a dramatic drop in New York’s crime rate, and like his patron, became a national media darling following his cool performance in the immediate aftermath of the 9/11 attacks in 2001.

But later in the decade, Kerik (pictured as he appears today) fell fast and hard as scandal after scandal unfolded in the New York press. His extramarital affair with publishing queen Judith Regan was prime fodder for tabloids, but his shady financial dealings are what landed him in prison for three years.

Kerik got out this past May a changed man. While in prison, he saw first-hand the upside-down insanity of the criminal justice system on which he’d built his life and previous reputation. Kerik is now on the media circuit, not in an attempt to rebuild his personal reputation, but as a born-again reformer who now sees the injustice in mandatory sentencing laws.

Despite his earlier position as the country’s best-known policeman, he now claims that before going to prison himself, he had no idea that nonviolent offenders could have their lives destroyed by the system for almost nothing.

In an appearance earlier this month on NBC’s Today Show, Kerik pulled a nickel from his pocket and told interviewer Matt Lauer, "I had no idea that for 5 grams of cocaine, which is what that nickel weighs, 5 grams, you could be sentenced to 10 years in prison," Kerik said.

His facts were a bit off — the minimum at the time Kerik went to jail was five years, not 10 — but it was the principle that mattered.

“Anybody that thinks that you can take these young black men out of Baltimore and D.C., give them a ten-year sentence for five grams of cocaine, and then believe that they're going to return to society a better person ten years from now, when you give them no life improvement skills, when you give them no real rehabilitation?” he told Lauer. “That is not benefiting society.”

While some may dismiss Kerik’s new viewpoint as nothing but a flip-flop prompted by his own traumatic experience — sort of the reverse of the cliché, “a conservative is just a liberal who’s been mugged” — Jennifer Eaglin of New York University’s School of Law says that his message needs to be taken seriously, regardless of the messenger or how he arrived at it.

“With more than 2.2 million people incarcerated in the United States, and 25 percent of adults in this country with a criminal record, Kerik only learned of the systemic failures once he entered federal prison – a system that has grown by 800 percent since 1980,” Eaglin wrote, in an essay for the law school’s Brennan Center for Justice. “Kerik suggested that no one can understand the horror of this system without spending time behind bars. Perhaps that is too drastic. But we can learn from Kerik’s perspective. It should not take a stint in prison for someone to oppose mass incarceration.

Watch Kerik’s Today Show interview, below.

SOURCES: New York Post, Brennan Center For Justice, NBC Today Show, Albany Times-Union