Jon Krakauer’s new book, “Missoula: Rape and the Justice System in a College Town,” follows Rolling Stone’s botched reporting of an alleged gang rape at the University of Virginia.

“Missoula” is quite the opposite. The author of “Into Thin Air” and “Into the Wild” is a meticulous researcher and respected journalist whose new book about an epidemic of rape at the University of Missoula, may err, if it errs at all, on the side of over-reporting and/or under-evaluating.

Krakauer’s intent is to use Missoula, Montana, as the lens through which to view the national problem of acquaintance rape, in particular, and the relatively infrequent prosecution of rape.

He looks at rape in Missoula and the resident University of Missoula from 2010 through 2012. He interviews young female students who’ve been raped, follows the legal negotiations and trials, profiles some of the prosecutors and accused rapists, and examines the culture of the university and the winning Grizzly football team.

Missoula, the state’s largest city, has 70,000 residents, 42 percent of whom have bachelor’s degrees or higher vs. 28 percent for the rest of the nation.

Because of what was termed an epidemic of rape, the Department of Justice launched an investigation into the University of Missoula, the Missoula County Attorney’s Office and the Missoula Police Department.

The DOJ cited the agencies’ “failure to investigate reports of sexual assaults against women,” which, according to the charges, amounted to gender discrimination. Few of the 80 rapes reported over a three-year period were prosecuted, and Krakauer looks at some of those.

The statistics on rape are shocking. In 2014, the CDC reported that 19.3 percent of American women had been raped and that 1.6 million were raped in the 12 months preceding the survey that used data from 2011.

Additionally, the U.S. Department of Justice reports that, in the period between 1995 and 2013, women 18 to 24 experienced the highest rate of rape and 0.7 percent of this group are sexually assaulted annually — 110,000 women.

These numbers are misleading because 80 percent of rape victims don’t report the crimes. Only 0.4 to 5.4 percent of rapes are prosecuted. And 0.2 percent of those prosecutions result in conviction that includes jail time.

More than 90 percent of the time, the rapist gets away with the crime. To set the record straight, the prevalence of false accusations is between 2 and 10 percent.

Krakauer learns that repeat offenders are responsible for a majority of acquaintance rape. In a sampling of 1,882 24-year-old men attending UMass Boston, 63 percent of those identified as the 120 “undetected” rapists were responsible for 436 rapes, or an average of six assaults per rapist.

Of those 120 rapists, 76 were repeat offenders. “A very small number of men in the population, in other words, had raped a great many women with utter impunity,” writes Krakauer. Subsequent studies replicated these serial rapist findings.

There was clearly a problem at the University of Montana, especially among its privileged and entitled Grizzly football team that has won 12 straight conference titles prior to 2012. The spate of rapes at the university provoked national media attention, though it turns out that 80 rapes over three years is on a par with the rest of the country.

“Rape, it turns out, occurs with appalling frequency throughout the United States,” writes Krakauer, who began this quest for information after discovering that a good friend had been raped twice and suffered serious emotional and psychological problems as a result.

Krakauer tracked the trial and legal wrangling of Beau Donaldson, a Grizzly and a lifelong friend of Allison Huguet, whom he raped. After reading the account and her articulate and thoughtful responses at the trial and sentencing hearings, I came to believe she was a major reason why Donaldson was found guilty.

He did confess, and another woman he attacked also testified.

Cecilia Washburn charged Grizzly quarterback Jordan Johnson with rape, but she lacked the same presence of mind under oath and the same level of proof. Plus, the accused was the celebrated star quarterback.

Kirsten Pabst, former supervisor of the sexual-assault division at the Missoula County Attorney’s Office, quit her job and defended Johnson in court. Johnson was found not guilty and went back to playing football. Pabst ran for County Attorney and won.

“Missoula” provokes much thought and many questions. Why would a city and a university tolerate what can only be described as a permissive culture of violence toward women? The cost of the legal negotiations and proceedings, alone, has to be staggering.

Another thing Krakauer reveals is the stunning disconnect between the young man who rapes at the same time he works to be an upstanding member of his community. This level of compartmentalization is as baffling as the fact that the men’s comprehension of right and wrong seems to vanish upon entering college.

Krakauer provides some answers. Part of the reason so many rapists are able to offend with impunity is that our adversarial system of justice “has erected formidable procedural obstacles to conviction,” writes Richard A. Posner, noted legal scholar and author of “Problems of Jurisprudence.”

Given this adversarial system of justice, rape victims are justifiably afraid to report their crimes. But, writes Krakauer, by holding it in, they exacerbate the PTSD they most likely suffer. Only by talking about the sexual abuse are they able to experience some degree of healing.

“By speaking out, they are likely to encourage other victims to tell their stories, too, and may find that they’ve advanced their own recovery in the bargain.”

Rae Padilla Francoeur’s memoir, “Free Fall: A Late-in-Life Love Affair,” is available online or in some bookstores. Write her at rae.francoeur@gmail.com Read her blog at freefallrae.blogspot.com or follow her on Twitter at @RaeAF.