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February 14, 2019

"The Dark Figure of Sexual Recidivism"

The title of this post is the title of this new paper authored by Nicholas Scurich and Richard John now available via SSRN.  Here is its abstract:

Empirical studies of sexual offender recidivism have proliferated in recent decades. Virtually all of the studies define recidivism as a new legal charge or conviction for a sexual crime, and these studies tend to find recidivism rates on the order of 5-15% after 5 years and 10-25% after 10+ years.  It is uncontroversial that such a definition of recidivism underestimates the true rate of sexual recidivism because most sexual crime is not reported to legal authorities, the so-called “dark figure of crime.”

To estimate the magnitude of the dark figure of sexual recidivism, this paper uses a probabilistic simulation approach in conjunction with a.) victim self-report survey data about the rate of reporting sexual crime to legal authorities, b.) offender self-report data about the number of victims per offender, and c.) different assumptions about the chances of being convicted of a new sexual offense once it is reported.  Under any configuration of assumptions, the dark figure is substantial, and as a consequence, the disparity between recidivism defined as a new legal charge or conviction for a sex crime and recidivism defined as actually committing a new sexual crime is large.  These findings call into question the utility of recidivism studies that rely exclusively on official crime statistics to define sexual recidivism, and highlight the need for additional, long-term studies that use a variety of different measures to assess whether or not sexual recidivism has occurred.

February 14, 2019 at 10:41 AM | Permalink


Without having read the paper, aren't all recidivism statistics subject to the "dark shadow'? That is, to recidivist new crimes that aren't discovered?

Posted by: Fat Bastard | Feb 14, 2019 1:57:11 PM

Fat Bastard has nailed it.
This "study," which right at the start gets the reported recidivism rates wrong (they are more like 3%), then goes on to say that, they "think" that sex crimes are underreported so therefore they can exagerate stats.
So like the Social Justice Puritans that claim without any substance that your daughter is more likely to be raped in college than in the Congo, are now attempting to put forth a "new" idea that all the studies that have ever been done in history that show that sex offenders re-offend less than any other crime--except for homicide--are now super dangerous?
Oh, I forgot. They also cheat the stats on the re-offend rate after a number of years. 25 percent??? That is a lie. This is not science. This is just more idiocy that is washing over any kind of scientific study in the West. It is bogus. It is nothing but idiocy run amuck.

Posted by: restless94110 | Feb 14, 2019 3:40:27 PM

Well I did skim the paper and it relies on an assertion that sexual offenses are underreported. But doesn't say to what extent other crimes are underreported. And I suppose an unreported crime cannot be a solved crime contributing to recidivism stats, I still think the paper has some infirmities along these lines.

Posted by: Fat Bastard | Feb 14, 2019 4:46:16 PM

This is pseudo-science of the worst kind. When one models the unknown one can produce a model to support any outcome one likes. Feminists do this all the time with rape statistics. One takes a truism--not every crime is reported--and then make wild ass assumptions to show that crime is vastly, hugely. bigly underreported. What makes this comedy routine especially pernicious is that if anyone tries to argue the other direction--that not all claims of sexual violence are true--then one is immediately accused of being a sexist, a stooge protecting the guilty, or worst of all being a member of the socially disfavored class.

Posted by: Daniel | Feb 14, 2019 4:56:08 PM

This is just another horse sh*t study based on nothing. It is designed to undermine the correct and myriad studies that have shown the actual low recidivism rates of sex offenders.

Posted by: Book38 | Feb 14, 2019 5:50:45 PM

Dr. Scurich is employed, outside of academia, by a risk-assessment consultancy called TAG, founded by none other than Dr. Death, Park Dietz, and employs mostly retired FBI agents. These guys' whole business model is dependent on fear-mongering.

Posted by: Fat Bastard | Feb 14, 2019 6:33:02 PM

What is particularly troublesome with this research is that it’s research subjects are from only one category out of hundreds of categories of criminal offenders - the sex offender, (Forgive me for lumping them together). This study could have been far more believable to the average reader if it would have focused it's scientific efforts on all law breakers. There is one fact that is indisputable; ALL crimes are underreported. Could it be that these researchers concentrated their study on sex offenders due to the aggregate harm most offenders cause to the victim? Drunk driving accidents also cause indelible harm to the victim(s). (if the victims don't die from the effects of the driver who is drunk). How many miles can a drunk driver travel before he or she is pulled over an issued a DUI? How many miles can a drunk driver travel before this lethal driver hits another vehicle and kills, or permanently injures innocent commuters, some of them children? Any scientific study should adhere to strict, unbiased methodologies and protocols. I wouldn’t be so compelled to commenting here if the victims of drunk drivers was a negligible amount. So, I will share the latest drunk driver fatalities in America with the readers of this blog and you decide for yourselves if this category of criminal offenders should have been included in this study...29 drunk driving fatalities, not a year, not a month, but A DAY on our streets. And finally, this statistic could have easily been inserted in this aforementioned study... In 2016, more than 1 million drivers were arrested for driving under the influence of alcohol or narcotics. That’s ONE PERCENT of the 111 million self-reported episodes of alcohol-impaired driving among U.S. adults each year. ( FBI statistics)

Posted by: tommyc | Feb 15, 2019 10:15:35 AM

The moment this duo cited the works Abel, Langevin, Prentky, and Ahlmeyrr, I knew that this was going to be a poorly devised, biased fluff piece.

Posted by: Derek Logue of OnceFallen.com | Feb 15, 2019 12:09:54 PM

I couldn't finish my comment for some reason on my phone so let me finish for the sake of those who don't understand why citing these 4 research studies to apply to recidivism studies are asinine.

The Prentky Study was only of a subset of SOs that already reoffended and were from a civil commitment program. Prentky himself warned his study is not indicative of SOs as a whole.

The Langevin study took the Prentky study to the next level -- he removed people who had not reoffended in 15 years under the guise of having been unable to find record of them. Generally, no one makes a record of non-recidivism.

Ahlmeyer uses polygraphs in a setting where those who cooperate get rewards for telling researchers what they want to hear. It is the same flaw that doomed the Butner study.

The Abel study was of paraphilias, not pedophilia as John & Scurich claim. That included consensual homosexual activity since that was considered deviant at the time of the study. But they use the number of ACTS and assume each are also indicative of number of victims. Abel even notes in that study that sex crimes were often limited to a small number of victims.

It should also be noted that using multinational studies to determine American sex crime rates is just plain stupid. After all, the USA casts a far wider net than most European countries, Australia, and even Canada.

These two "researchers" obviously have a vested interest in shamelessly promoting this flawed report.

Posted by: Derek Logue of OnceFallen.com | Feb 15, 2019 7:09:14 PM

One of the problems of the underestimation arguments is no one has estimated the prevalence of unreported sex crimes in the general population with any accuracy. You can't just say that recidivism is underestimated when you don't have a control group. It might be underestimated, but it also might be less than the general population. A lot of things can be labeled a sex crime these days.

Posted by: Andrew Nicholson | Feb 15, 2019 8:06:50 PM

This article argues that because of the high rate of unreported sexual offenses, it is wrong to describe the rate of sexual re-offending as “low”. It suggests in particular that my widely quoted article 2015 article in Constitutional Commentary, (“Frightening and High”: The Supreme Court’s Crucial Mistake About Sex Crime Statistics), is therefore misleading. However, this new piece does not in fact disagree with either that article’s critique of the Court’s mistaken reliance on a casual popular source, or the way in which the Court’s ungrounded empirical assertions have affected many later decisions by other courts. Nor does it disagree with the claim that the reported rates of sexual re-offending by registrants are not high. It rather argues a different point: that the rate at which registrants actually commit new sexual offenses must be higher than the rate at which they are convicted or arrested for them, because so many sexual offenses are unreported. The article also develops a complicated probabilistic model to estimate what the “real” rate of sexual re-offending by registrants is—that is, the rate that would include unreported offenses they commit.

Of course, almost by definition, one cannot really know for sure the actual rate at which unreported crimes occur. But efforts like those in this article to estimate them can be useful. Of course, any such efforts must unavoidably rely on various assumptions, as these authors concede, and the assumptions they employ in constructing their complicated stochastic model are different than those others might make. But for those interested in legal policy rather than in statistical methodology, the important observation to make about this article is different.

As explained in several amicus briefs recently filed in the Court by a group of 18 scholars across six disciplines, the real question is not the absolute rate at which people re-offend, but how that rate compares to the rate of sexual offending by other groups who are not subject to the registry or its companion rules—what one can call their relative offense rate. Special burdens on registrants cannot be justified unless the risk they pose is importantly larger than the risk posed by other groups who are not so burdened. So for legal purposes, the question is this relative risk, as measured by their re-offense rate compared to the sexual offense rate of other groups. This important point is missed entirely by this article. Because the proper focus is on relative risk, the precise rate of unreported sexual offenses is likely to be irrelevant to the legal issues.

There is no reason to think a larger proportion of sexual offenses committed by registrants go unreported than do sexual offenses committed by others. If the proportion of total offenses that go unreported is same across groups, then if one group’s reported offense rate is the same as another group’s, their “total rate”—reported plus unreported—is also going to be the same. In fact, it is plausible to think that a higher proportion of offenses committed by registrants come to the attention of law enforcement authorities, than for other groups. If police investigating sexual crimes give particular attention to those with a history of sexual offending, then that group’s sexual offenses will more often be detected than will sexual offenses committed by others. (Note that this is true even in the absence of a registry accessible by the public). In that case, a focus on the rates of reported sexual offenses overstates the rate by registrants, relative to the sexual offense rate of others. This is particularly noteworthy because several studies have found that 95% of more of all reported sexual offenses are committed by first offenders.

In short, the central claim made in recent briefs filed in the Court on behalf of social scientists—that large groups of registrants burdened by various rules in fact pose no special risk of sexual offending—is unaffected by the claims made in this article.

Of additional interest, perhaps, are some recent reports (overlooked by The Dark Figure of Sexual Recidivism), that indicate that the proportion of sexual offenses which go unreported has declined in recent years, perhaps because of increased public attention to the problem of sex offenses. It seems the proportion of sexual offenses that go unreported now approach that for nonsexual crimes. Rachel Morgan and Jennifer Truman, Criminal Victimization, 2017, Dept. of Justice, Bureau of Justice Statistics (December 2018, NCJ 252472), https://www.bjs.gov/content/pub/pdf/cv17.pdf, at 7 tbl.6 (showing that the proportion of sexual assaults reported to the police increased significantly in 2017, to 90% of the reporting level for violent crime generally). This trend appears to have begun some years ago, as studies from 2011 show a reduction in the proportion of sexual offenses against child victims that go unreported. Finkelhor, Ormrod, Turner, & Hamby, School, Police, and Medical Authority Involvement With Children Who Have Experienced Victimization, 165 ARCHIVE OF PEDIATRIC AND ADOLESCENT MEDICINE 9 (2011)). Police are particularly likely to know about sex offenses committed against children by adults (as opposed to the large share that were committed by other children). Id.

Posted by: Ira Ellman | Feb 18, 2019 2:27:46 PM

I'd be more inclined to believe there was no intentional acts of bias from these two researchers if:

1. They didn't attempt to use apologetics to justify including controversial studies largely debunked by many researchers and reports that relied on junk science.

2. These "researchers" didn't work for agencies peddling risk assessment software to the masses.

Posted by: Derek Logue of OnceFallen.com | Feb 18, 2019 9:55:39 PM

And in the final analyses any person looking for the truth always considers the PREPONDERANCE of evidence, data, research in making any determination...There is no need to take sides when one is searching for the truth. Here is another of many truth based responses that seriously considers the preponderance of evidence...

Posted by: tommyc | Feb 19, 2019 6:50:32 PM

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