The Myth of the “Dark Figure” of Underreporting
Derek W. Logue of
Created 24 May 2019, Updated 21 July 2023


Underreporting is an appeal to ignorance; quite frankly, no one can accurately estimate the number of undetected sex crimes (or any crime). Because there is no way to prove a definitive crime rate, the door remains open for the initiated to perceive even the most outlandish claims of high rates of reoffending as factual. This article examines the myth of underreporting in great detail and the difficulties in debunking these outlandish claims of underreporting. This article concludes that our level of sex crime underreporting is grossly over-reported.


To the average person the term “dark figure of crime” likely invokes some scary movie imagery (like a shadow stalking a damsel in distress), but in criminology terms, it is merely a fancy way of saying all crimes that are neither reported nor recorded by law enforcement agencies (unreported crime). Belgian mathematician and sociologist Adolphe Quetelet was the credited with coining the term in 1832.[1]  It is generally accepted that some crimes go unreported, but since unreported actions are unreported, we can only speculate just how often crimes go unreported.

Trying to come up with this so-called “dark figure” opens the door to the logical fallacy “Ad ignorantiam” (argument/ appeal to ignorance). Ad Ignorantium defined is “the assumption of a conclusion or fact based primarily on lack of evidence to the contrary. Usually best described by, ‘absence of evidence is not evidence of absence.’” “X is true because you cannot prove that X is false, or X is false because you cannot prove that X is true.”[2]  Thus, when a victim advocate group makes the bold claim that “sex offender recidivism is higher than reported because most sex crimes go unreported,” they are fully aware that there is no way to prove or disprove that assertion. It is a common tactic to attempt to discredit the long history of finding extremely low re-offense rates among people convicted of sex crimes.

Because there is no way to accurately study the amount of unreported crime, the best we can do is reliance on assumptions and estimations. Many of the studies critiqued in this work rely on tactics such as self-reports of victims and offenders, complex statistical schematics used by “sports-betters, gamblers, and even weather forecasters”[3] , and controversial tactics like the polygraph to reach their results.

Even the dubiously-named “SMART Office” has to admit that there are great difficulties associated with making assumptions about the link between underreporting and people listed on the sex offense registry:

“Drawing firm conclusions about the extent of sex offender recidivism can be difficult due to a number of factors. First, although there is universal agreement that the observed recidivism rates of sex offenders are underestimates of actual reoffending, the magnitude of the gap between observed and actual reoffending remains subject to debate. As a result, conclusions about the extent of sex offender recidivism and the propensity of sex offenders to reoffend over the life course inherently involve some uncertainty. Second, measurement variation across studies often produces disparate findings that can be difficult to interpret. Comparing and corroborating findings can be difficult for the same reason. Third, short follow-up periods and small sample sizes limit the generalization of certain findings. Drawing a firm conclusion about the propensity of specific subgroups of sex offenders to reoffend over the life course is particularly difficult, as sample sizes often fall to unrepresentative levels as follow-up periods grow longer.”[4]

To study this issue in detail, we must begin by looking at the largest national study on underreported crimes, the National Crime Victimization Survey.


The largest attempt at determining the amount of underreporting is the National Crime Victimization Survey. “The Bureau of Justice Statistics’ (BJS) National Crime Victimization Survey (NCVS) is the nation’s primary source of information on criminal victimization. Each year, data are obtained from a nationally representative sample of about 135,000 households, composed of nearly 225,000 persons, on the frequency, characteristics, and consequences of criminal victimization in the United States. The NCVS collects information on nonfatal personal crimes (i.e., rape or sexual assault, robbery, aggravated and simple assault, and personal larceny) and household property crimes (i.e., burglary, motor vehicle theft, and other theft) both reported and not reported to police…For each victimization incident, the NCVS collects information about the offender (e.g., age, race and Hispanic origin, sex, and victim-offender relationship), characteristics of the crime (e.g., time and place of occurrence, use of weapons, nature of injury, and economic consequences), whether the crime was reported to police, reasons the crime was or was not reported, and victim experiences with the criminal justice system.”[5]

The following questions are asked in the NCVS survey[6]  (noting that because the focus is on sex crime reporting only questions related to sex crimes are mentioned):

41a. (Other than any incidents already mentioned,) has anyone attacked or threatened you in any of these ways – (Exclude telephone threats) – Read each category.

(a) With any weapon, for instance, a gun or knife –
(b) With anything like a baseball bat, frying pan, scissors, or stick –
(c) By something thrown, such as a rock or bottle –
(d) Include any grabbing, punching, or choking,
(e) Any rape, attempted rape or other type of sexual attack –
(f) Any face to face threats – OR
(g) Any attack or threat or use of force by anyone at all? Please mention it even if you are not certain it was a crime.

43a. Incidents involving forced or unwanted sexual acts are often difficult to talk about. (Other than any incidents already mentioned,) have you been forced or coerced to engage in unwanted sexual activity by – Read each category.

(a) Someone you didn’t know –
(b) A casual acquaintance – OR
(c) Someone you know well
Did any incidents of this type happen to you?  
44a. During the last 6 months, (other than any incidents already mentioned,) did you call the police to report something that happened to YOU which you thought was a crime?

“Respondents who answers affirmatively to any of the short-cue screening items are subsequently administered a crime incident report (CIR)… For instance, a separate screening question cues respondents to think of attacks or threats that took place in specific locations, such as at home, work, or school. Respondents who recall a sexual victimization that occurred at home, work, or school and answer affirmatively would be administered a CIR even if they did not respond affirmatively to the screening question targeting sexual violence…Although the CIR does not ask respondents if psychological coercion was used, one screening question targeted to rape and sexual violence asks respondents if force or coercion was used to initiate unwanted sexual activity.”[7]

Despite being the largest defined study on attempting to determine a true crime rate of America (the NCVS has a larger number than even the Nielsen TV viewer studies), there are some caveats to accepting the numbers given by the NCVS.

Sample sizes for sex offenses are incredibly small  

The NCVS understands its own limitations, as noted in the 2010 NCVS:

“While the change in the rape or sexual assault rate from 2009 to 2010 is significantly different at the 90%-confidence level, care should be taken in interpreting this change because the estimates of rape/sexual assault are based on a small number of cases reported to the survey. Therefore, small absolute changes and fluctuations in the rates of victimization can result in large year-to-year percentage change estimates. For 2010, the estimate of rape or sexual assault is based on 57 unweighted cases compared to 36 unweighted cases in 2009. The measurement of rape or sexual assault represents one of the most serious challenges in the field of victimization research.” In 2010, there were 57 “unreported cases” out of sample size of nearly 71000 people: In 2010, 40974 households and 73283 individuals age 12 and older were interviewed for the NCVS. Each household was interviewed twice during the year. The response rate was 92.3% of households and 87.5% of eligible individuals.”[8]  

In other words, underreporting rates (and sex crime rates in general) in the NCVS can change drastically by just a few reports.

Since 2000, the underreporting rates have dropped to a low in 2010 and then risen in the 2010s, but since these numbers are influenced by roughly 100 or so annually reported in the NCVS, the NCVS repeatedly warns us to use caution in interpreting these numbers:

  • 2003 NCVS: 67.3% of rapes and attempted rapes (attempts included verbal threats of sexual violence) and 53.2% of sexual assaults go unreported (Note: Between 2003-2005, sex assaults/ rapes were consolidated)
  • 2005 NCVS: 61.7% of rapes/ sexual assaults and attempts go unreported
  • 2006 NCVS: 58.6% went unreported
  • 2007 NCVS: 58.4% went unreported
  • 2008 NCVS: 58.6% went unreported
  • 2009 NCVS: 44.6% went unreported
  • 2010 NCVS: 50% went unreported
  • 2011 NCVS: 73% went unreported
  • 2012 NCVS: 72% went unreported
  • 2013 NCVS: 65.2% went unreported
  • 2014 NCVS: 66.4% went unreported
  • 2015 NVCS: 67.5% went unreported
  • 2016 NCVS: 76.8% went unreported
  • 2017 NCVS: 59.6% went unreported

One possibility for the increases could likely be traced to recent controversies like the high-profile trials of Jerry Sandusky[9]  and Larry Nassar, the “#MeToo Movement”, the claims of widespread rape on college campuses, the revival of decades-old sex abuse accusations against the Catholic Church, the 2016 Presidential Election, and the appointment of Brett Kavanaugh to the US Supreme Court. The constant bombardment of these headlines could have increased the belief of underreporting throughout the 2010s. At the least, it could influence the answers to NCVS questions.

Definition of Rape, Sexual Assault, and “Attempts” are ambiguous

The NCVS defines rape as, “Forced sexual intercourse including both psychological coercion and physical force. Forced sexual intercourse means vaginal, anal, or oral penetration by the offender(s). This category also includes incidents where the penetration is from a foreign object, such as a bottle. Includes attempted rape, male and female victims, and both heterosexual and same sex rape. Attempted rape includes verbal threats of rape.” Sexual assault is defined as, “A wide range of victimizations, separate from rape or attempted rape. These crimes include attacks or attempted attacks generally involving unwanted sexual contact between victim and offender. Sexual assaults may or may not involve force and include such things as grabbing or fondling. Sexual assault also includes verbal threats.”[10]

In the NCVS, both the definition of attempted sexual assault and attempted rape includes “unwanted sexual contact” and “verbal threats”. In this age of “#MeToo” and other feminist-centered awareness events, we must ask ourselves what a modern person (particularly one of the feminist or other victim-centric persuasion) might think qualifies as an “attempt.” Consider the statement posted on the Simple Justice criminal defense blog from 2018, in response to a white paper from National Sexual Violence Resource Center and Urban Institute:

“It’s now official; ‘stare rape’ is sexual violence, as is flirting, asking personal questions and the attempted touching of a non-sexual body part, such as, I guess, hand-shaking. Not only will this be sufficient cause for termination, if not public castigation, but it will be included in an empirical analysis of the prevalence of sexual violence. Was I a witness to sexual violence on the subway? It’s all according to how one defines it. Is it a crime to stare? What constitutes a stare from a look, or a leer? Many such offenses are popularly defined by the sensibilities of the victim, whether it made her feel uncomfortable, but this provides no clue to the “perpetrator” of stare rape that he’s looked beyond the point of acceptability to that particular “survivor” and should have averted his eyes.”[11]  To some, it may seem like a silly notion that merely looking at a woman too long is on par with physical rape, but in 2008, there was a serious attempt to push to criminalize looking at a child too long in the state of Maine.[12]

Cathy Young, a critic of modern feminism, wrote, “Forty years ago, feminist reformers successfully challenged the discriminatory treatment of rape complainants, from the requirement of physical resistance to condemnations of a woman’s “unchaste character.” Feminist advocacy also deserves credit for clarifying that forced sex is always rape, even in a relationship. (I am talking here about being forced by physical violence, restraint or threats, or being subjected to sexual acts while physically helpless.) But the anti-rape activism that emerged in the 1990s and has surged on college campuses and on the Internet in recent years goes far beyond that. Today, it not only embraces an absolutist version of “no means no,” in which any hint of reluctance must halt further attempts at sexual intimacy; the movement also insists that only a clear (and sober) ‘yes’ means yes…”

“Meanwhile, there is little regard for the preferences of people who like intuitive give-and-take rather than requests and directions. Sensual, playful or raunchy bedroom talk is very different from compulsory questions checking for a clear signal that you’re not crossing a line. Reluctance to engage in frank sexual communication is treated solely as a puritanical hang-up rather than a valid desire to preserve some spontaneity or dignity. And the wrong kind of communication, such as persuading an initially hesitant partner, is equated with sexual assault. Despite its scorn for reticence, the new sexual revolution has a deep puritanical streak. Consensual sex is viewed as always under control, the result of a rational, fully autonomous choice. In this vision, there is either unequivocal ‘enthusiastic consent’ or reluctant submission. In real life, though, there are many other possibilities… It is time to rethink this crusade, which criminalizes bad or uncomfortable sex, thereby trivializing actual sexual violence.”[13]

There is a battle to pass laws to make deceiving a woman in order to get her to sleep with you is a sexual offense.[14]  Many women believe having sex while intoxicated equates to rape because she cannot consent while intoxicated.[15]  A campus poster generated controversy when it made an anti-rape poster with a smiling heterosexual couple smiling and drinking alcohol; the tagline was, “Jake was drunk. Josie was drunk. Jake and Josie Hooked Up. Josie could not consent. The next day JAKE was charged with RAPE.”[16] Four states (CA, IL, NY, CT) have passed an “affirmative consent law,” a.k.a., a “Yes Means Yes law,[17]  a rather vague standard of law that stipulates “silence or lack of resistance” does not in itself demonstrate consent. Some women believe consent can be pulled due to a regretful sexual encounter.[18]

Because what constitutes an “attempt” is quite vague within the NCVS, it is open to interpretation. It is not difficult to imagine that in our current climate (as illustrated in the above examples) that the very definition of rape or sexual assault in itself is vague. Because these instances were never reported, these incidents reported to the NCVS are not reviewed by law enforcement agencies. The only standard is a follow-up “crime incident report” conducted by BJS researchers.

The current NCVS does not adequately cover the demographics of the perpetrators of the crimes reported. Even if they did, the prior criminal record of the alleged perpetrator would likely be unknown. The NCVS is virtually useless as a tool to determine the level of unreported re-offenses by registered persons. Furthermore, the NCVS only covers crimes against anyone over 12 years of age, so sex crimes against anyone under 12 is not covered in the report.

Children under 12 are not covered in the NCVS

In an attempt to rectify certain issues with the NCVS, the DOJ conducted a study called “Sexual Assault of Young Children as Reported to Law Enforcement: Victim, Incident, and Offender Characteristics” in 2000. Since the NCVS only relates to victims 12+ years of age, the study relied on the FBI’s National Incident-Based Reporting System (NIBRS).  While there is no feasible way to survey children on unreported sex crimes, this study offers up another X factor to further complicate the issue: the number of sexual assaults committed by juveniles who are likely not a registered sex offender. The study found that juveniles made up 23.2% of total sex crimes against children: 40% of offenders of children under age 6 and 39% of offenders against children ages 7-11 were juveniles; and the single age with the greatest number of offenders is 14 (p. 8).[19]  

The NCVS does not cover false allegations

Victim advocates like to incorporate claims of “low rates of false reports” to minimize the impact of false allegations because it fits into their “sexual abuse as an epidemic” narrative. As stated in one prominent victim advocacy group:

“The prevalence of false reporting is low — between 2% and 10%. For example, a study of eight U.S. communities, which included 2,059 cases of sexual assault, found a 7.1% rate of false reports. A study of 136 sexual assault cases in Boston found a 5.9% rate of false reports. Researchers studied 812 reports of sexual assault from 2000-2003 and found a 2.1% rate of false reports.”[20]  

Assuming this was true, we can reasonably conclude that between 2% and 10% of unreported incidents were falsely reported to the NCVS and between 2% and 10% of registered persons that are currently on the public are falsely accused. However, there are also many studies that contradict the narrative of low levels of false rape claims.[21]  


Underreporting studies often fail to bother to ask why crimes, including sex crimes, are not reported in the first place. Of course, we will never know if the event crosses the threshold into being a crime since it was not reported, much less investigated, by trained law enforcement. Since sexual offenses are seen as on par with murder in American society, then it seems unusual for such serious offenses to go unreported.

The Harris and Hanson’s 2004 recidivism report cited a Besserer and Trainor (2000) study that “showed that sexual assault had the highest percentage of incidents that were not reported to police (78%). When respondents were asked why they did not report sexual victimization to the police, 59% of the respondents stated that the “incident was not important enough” to report. Consequently, readers may wonder what counts as a sexual assault. The Besserer and Trainor (2000) victimization study used a very broad definition of sexual assault. They counted all attempts at forced sexual activity, all unwanted sexual touching, grabbing, kissing, and fondling, as well as threats of sexual assault (Jennifer Tuffs, personal communication, January 15, 2003). Their broad definition undoubtedly included some behaviours that do not conform to the popular image of a sexual offence.”[22]

At one time the NCVS also published a supplement to the annual reports entitled “Statistical Tables” which contained numerous statistics not included in the annual reports. The most recent of these Statistical Tables covered the year 2008. Table 104 covers “Percent distribution of reasons for not reporting victimizations to the police, by victim-offender relationship and type of crime,” offers various reasons for failing to report an incident. The following answers were given as reasons for non-reporting, noting that the answers were different when the incident involved a stranger and a non-stranger. The answers given in the 2005 Statistical Tables are offered as a comparison:

  • 2008 NCVS Stat Table 104: Percent distribution of reasons for not reporting victimizations to the police, by victim-offender relationship and type of crime (Noting that estimates are based on less than 10 sample cases for each answer given; also note that multiple reasons were given so the numbers won’t add to 100%)
  • Stranger: Reported to another official (47.9%); Offender Unsuccessful (38.8%); Private/ Personal Matter (13.3%)
  • Non-Stranger: Private/ Personal Matter (25.1%); Fear of Reprisal (14.8%); Reported to another official (10.8%); Offender unsuccessful (8.8%); Police inefficient/ biased/ ineffective (5.5%); Police won’t wantto be bothered (3.2%);
    Lack of Proof (3%)[23]
  • 2005 NCVS Stat Table 104:  Percent of reasons for not reporting victimizations to the police, by victim-offender relationship and type of crime (Noting that estimates are based on less than 10 sample cases for each answer given; also note that multiple reasons were given so the numbers won’t add to 100%)
  • Stranger: Reported to another official (49.6%), Police don’t want to be bothered (19.9%), Offender unsuccessful (12.7%), Fear of reprisal (11%), and Police inefficient, ineffective, or biased (6.9%). Non-stranger: Other Reasons (47%), Private or personal matter (31.1%), Police don’t want to be bothered (10.8%),
    Report to another  official (5.1%), Police ineffective, inefficient, biased (2.8%), and Too incontinent, time consuming (2.4%)[24]

While the Statistical Charts may offer a glimpse into the various reasons for failing to report an incident, it is important to remember that each answer came from a very small sample. The NCVS is a survey of roughly 70k to 100k households annually, yet the statistics on reasons for failing to report is derived from sample sizes of about 10 people or less.

We have placed an emphasis on sex crimes, but Researcher Debra Patkin states that under-reporting for crime in general is under-reported; citing the 1999 NCVS, Patkin notes 64% of overall crime goes unreported.[25]  

We may never know if an incident would have been considered a crime, but based on the studies on reasons for underreporting, we can conclude that many people, even the subjects of these studies, felt many unreported incidences do not rise to the level to criminal activity. Why we emphasize sex crimes in America is worthy of entire volumes of work, but like any other irrational fear—Ebola, terrorism, Communism—the actual danger to America is extremely small. Fear of the unknown is perhaps the greatest of fears, and if so, that is why the underreporting myth remains underreported. But that alone is not the reason. Because fear sells, there are plenty of charlatans, hucksters, and snake-oil peddlers willing to peddle this fear to Americans for profit.


Proponents of the myth of underreporting rely on the following sequence of statements:

  1. Sex Crimes are underreported
  2. Some people convicted of sex crimes and placed on the registry do reoffend
  3. Therefore, “sex offenders” are the cause of underreporting

This assumption is a non sequitur. Proponents never consider the fact that most sex crimes are not committed by those on the registry; in one major study, it was found that around 95% of sex crime arrests were of people with no prior sex offense record. [26]  It has also been an established fact that those convicted of sexual offenses commit subsequent sexual offenses at less than 1% annually.[27]  

This assumption relies upon the closely-tied myth of “high re-offense rates” to make the jump from underreporting in general to the assumption must unequivocally the result of “registered sex offenders.” Because people simply don’t want to believe that sex crimes have an extremely low re-offense rate, confirmation bias sets in.  

In the SMART Office report, Roger Przybylski makes his case by citing similar studies of general underreporting by stating, “Due to the frequency with which sex crimes are not reported to police, the disparity between the number of sex offenses reported and those solved by arrest and the disproportionate attrition of certain sex offenses and sex offenders within the criminal justice system, researchers widely agree that observed recidivism rates are underestimates of the true reoffense rates of sex offenders.”[28]  

Przybylski’s statement is a textbook non sequitur:

  1. Sex crimes in general are underreported,
  2. Not every sex offense claim leads to arrest,
  3. We pay attention to certain types of victims and offenders more than others,
  4. Therefore, reoffending by those convicted of sex crimes is grossly underreported.

The job of the SMART Office is to promote the federal Adam Walsh Act, so bias should be expected. But Przybylski is not an outlier when it comes to making such assumptions; in 2019, Nicholas Scurich (University of California, Irvine) and Richard S. John (University of Southern California) published a report entitled “The Dark Figure of Sexual Recidivism”, in which they proclaim, “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 of 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, a principle known as the “dark figure of crime.”[29]

The Scurich and John report can be construed as an exercise in confirmation bias; Richard S. John is associate professor of psychology and a research associate at the Center for Risk and Economic Analysis of Terrorism Events (CREATE) at the University of Southern California. His research focuses on normative and descriptive models of human judgment and decision making and methodological issues in application of decision and probabilistic risk analysis (PRA). He has consulted on a number of large projects involving expert elicitation, including analysis of nuclear power plant risks (NUREG 1150) and analysis of cost and schedule risk for tritium supply alternatives.

Nicholas Scurich, PhD, is “a tenured professor of Psychology and Criminology at the University of California, Irvine. In 2017 he joined TAG (“Threat Assessment Group”) as a consultant and lecturer in workplace misconduct mitigation. Dr. Scurich’s focus on misconduct risk assessment has included scientific studies of how to assess the risk of misconduct, how to deter dangerous behavior, how to make scientifically informed decisions about risky individuals, and how to communicate risk information. He frequently consults for the Department of Homeland Security on issues related to risk assessment and security. For example, he has worked with the TSA to help develop novel approaches to allocating security resources and screening of airline passengers based on risk.”

The report states, “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.”

As with the SMART Office report, Scurich and John rely upon a reliance of underreporting in general as the foundation of the argument. Scurich and John cements the non sequitur with an appeal to authority on page 5 by claiming it is “uncontroversial that longer follow-up periods will result in more sexual offenses and thus a higher rate of sexual recidivism.” As the fallacies go, if authorities believe there that there is higher recidivism, and we believe underreporting is true, then you must come to the conclusion that sex offenses by those convicted of sexual offenses must be far higher than observed. There is no way to prove or disprove the conclusion, so the average reader assumes this statement to be true.

Both the SMART Office report and Scurich and John report relied heavily on a number of controversial reports that have been called into controversy over the years:

  1. The 1997 Prentky study[30] : Made the controversial claim that after 25 years sex offenders’ recidivism is 52% for child molesters and 39% for rapists. However, these numbers were not a true re-offense rate, but a “survival/ failure rate”, i.e., “the estimated probability that child molesters would ‘survive’ in the community without being charged, convicted, or imprisoned for a sexual offense over the 25-year study period.” Prentky himself warned against misusing the stats, primarily because the study involved recidivists who were civilly committed between 1959 and 1985, meaning this was not representative of everyone on the sex offense registry. It is worth noting that even the SMART Office report recognized the limitations of the report, nor does it claim rates presented in the report as an accurate number.[31]
  2. The 2004 Langevin Study[32] : A fatally flawed study using a sample from a single civil commitment center, Langevin’s study purged people without rearrests after 15 years, and it expanded the definition of recidivist to include crimes committed before subjects were to be included in the study. In an earlier report of the same data set, Langevin and Fedoroff (2000) reported that they were able to obtain follow-up criminal history records for 378 (54%) of the first 700 cases assessed at Dr. Langevin’s clinic between 1969 and 1974. In the 2004 report, the offenders lacking criminal history records in 1994 and 1999 were eliminated from the sample. Such a decision would retain recidivists and eliminate non-recidivists. More than half the individuals in the sample were already recidivists by Langevin’s definition at the time of their evaluations, thus ensuring at least a 50 percent recidivism rate. Even the SMART Office report does not cite Langevin’s study.
  3. The 2000 Ahlmeyer study[33] : Both studies also use this study, which relied on polygraphs and self-reports. Polygraphs are inadmissible in court but utilized as intimidation tools. The Ahlmeyer study consisted of 60 adult male sexual offender (35 inmates and 25 parolees), which concluded that more incidents and victims were reported, but a second test reported low numbers though they concluded 80% were “deceptive.” But it is worth noting that polygraph studies have relied on self-reporting by the subjects and been conducted in settings where incentives were offered to subjects for cooperation. (the controversial 2007 Butner study is the most egregious examples of this.)
  4. The Gene Abel 1987 study[34] : Both the SMART Office and the Scurich and John articles cite Gene Abel’s work. Abel’s primary report covered “paraphilias.” Paraphilia means any act considered deviant by societal norms, which should not be confused with pedophilia; it seems Scurich and John failed to notice the difference. Abel’s study had a number of problems – few offenders were voluntary (which would compel false admissions), inclusion of non-criminal paraphilias such as consensual homosexual relations, and Abel lists an estimated number of acts and victims over a lifetime. Abel states the study suggested paraphiliacs, “through coercion or varying degrees of compliance, repeated acts are carried out with the same victims or partners”.

The Abel study actually debunks the Scurich and John report; Scurich and John use reports studying the subclass of particularly high-risk offenders to justify their claims of high levels of recidivism while the Abel study illustrates exactly why that is problematic. Abel provides a Mean and Median estimate of acts and number of victims. The Mean is the sum of all the numbers in the set divided by the amount of numbers in the set. The Median is the middle point of a number set, in which half the numbers are above the median and half are below. Scurich and John cited the highest number possible found in the Abel study, the mean number of estimated number of lifetime acts by those with male victims, listed in the Abel study as 281.7, but the researchers fail to mention the mean number, which is 10.1, far lower than the scarier number. Since half of those in the Abel study committed LESS than 10.1 paraphilic acts while the average (mean) number of acts was assumed to be 281.7, then there must be a small group of people that have grossly inflated the average. These small subgroups are the subjects of Langevin, Prentky, and the Ahlmeyer studies, the studies that incidentally give grossly inflated estimates of recidivism.

Scurich and John used studies relying on estimates to come up with a number to validate their own estimates. The duo used advanced statistical models such as Poisson distribution in order to amaze readers, but at the core is an estimate based upon what they personally feel it should be, specifically a high number. There is no discussion on the probability of false reporting of sex crimes, or of the vast discrepancy between rearrest and reconviction rates in the Scurich and John study (the SMART Office report also fails). But perhaps most importantly, The Scurich and John study suffers from a fatal design flaw in using estimates of underreporting in general to underreporting by registered persons.

The SMART Office report concludes, “While the magnitude of the difference between observed and actual reoffending needs to be better understood, there is universal agreement in the scientific community that the observed recidivism rates of sex offenders are underestimates of actual reoffending.”[35]  It cites the 2004 Harris and Hanson study [36]  to claim elevated recidivism levels, but the study is a multinational study so the results are not valid for understanding American recidivism. (In Canada, the age of consent was raised from 14 to 16 in 2008 [37] , while the age of consent in America is between 16 and 18, thus some sexual acts legal in Canada before 2008 were illegal in America.) However, the SMART Office study does not cite the Langevin or Prentky rates as true recidivism rates.

Scurich and John cite the Langevin and Prentky rates as accurate in their opinion, even arguing against the condemnation of the controversial Langevin study. Scurich and John attempt to shield their fallacies by making the following disclaimer:

“We do not endorse any specific sexual recidivism rate as the ‘correct’ one…there is no single, universal recidivism rate that describes all varieties of sexual offenders.” If this statement is true, then this research paper cannot even make any actual claims on sex crime re-offense at all. Yet, in the very next sentence, Scurich and John do just that, proclaiming, “By parity of reason, sweeping proclamations that ‘…only a minority of sex offenders recidivate’ (Calkins et al., 2014, p. 449)” are inapposite.” By parity of reason, the same sweeping proclamation that “the majority of sex crimes are vastly unreported” is equally inapposite. Despite the rhetoric and use of lofty speech, these two reports are no closer to the truth than the average citizen and rely of logical fallacies and confirmation biases.[38]  

A 2021 critique published in the “Behavioral Sciences & the Law” Journal concluded that the Scurich and John article “does not analyze data in the traditional sense; instead, it just interprets past scholarly work through the use of strong assumptions in a way that, for practitioners, is likely to be opaque and misleading (and, for us, strays into speculation, argument, or advocacy and away from objective research). Our simple calculations show that their findings are highly sensitive to their assumptions, and we conclude that courts and others should recognize Scurich and John’s work for what it is—a set of complex hypotheticals that are no more reliable than what judges and lawyers accomplish on their own by simply recognizing the basic problem that not all sexual offenses are reported.” [39]

The Authors of the 2021 study point out numerous flaws in the Scurich and John report, including:

  1. Scurich and John cannot know the extent of underreporting, and because they cannot possible know that amount, attempting to simulate a possible outcome is a pointless task since it relies purely on assumptions.
  2. Scurich and John relied heavily on recidivism studies with small sample sizes, ignoring the three large recidivism studies conducted by the USDOJ. They also gravitated towards studies that led to higher recidivism rates.
  3. Scurich and John assumes that reoffense propensity was a constant (“In other words, a person’s chance of reoffending is the same at year one
    as it is at year 25.”). Studies have consistently shown the likelihood of recidivism lowers over time.
  4. Scurich and John fail to take into account that stranger crimes, as well as crimes committed by those with prior sex offense records are more likely to be taken seriously, which makes underreporting of offenses committed by those with prior records less likely.[40]

The reasonable conclusion is that “The numbers (Scurrich and John)offer are inflated by the benchmarking choices they make, as well as the very strong (and inaccurate) underlying assumptions about reoffending behavior and victim and law enforcement behavior on which they rely.” In other words, Scurich and John made a fatally flawed mathematical formula that relied on assumptions and cherry-picked studies.

Emily Horowitz, citing a 2021 report by Ira Ellman, adds that “recidivism rates for those with prior sex-offense convictions are likely lower than research shows…In many ways, claims that sex-offense recidivism rates are faulty because of ‘underreporting’ are also, at their core, based on animus.”

Ellman highlights the key reasons sex offense underreporting is less common than currently believed:

  1. Victims are more likely to report sexual offenses committed by perpetrators whom they know have a prior sexual offense conviction;
  2. Police are more likely to follow up on reports by victims who identify the perpetrator as someone with a prior;
  3. Police are more likely to identify, and thus arrest, perpetrators with prior sexual offenses; and
  4. Prosecutors are more likely to file charges and win convictions in cases in which the alleged perpetrator has a prior sexual offense conviction.”[41]

Commonwealth v Torsilieri, No. 15-CR-0001570-2016 (Chester Co PA Super. Ct. 2022): Scurich and John study debunked in court

The Torsilieri case has been a lengthy challenge to Pennsylvania’s SORNA law. After this case was remanded by the PA Sup Ct to lower court in June 2020; this trial court concluded that the assumption that all Registered Persons pose a high risk of reoffending sexually” under the state’s SORNA law is unconstitutional

The court noted, “An irrebuttable presumption is unconstitutional where (a) it encroaches on an interest protected by the due process clause; (2) the presumption is not universally true; and (3) reasonable alternative means exist for ascertaining the presumed fact… we do not invade the liberties of citizens based on crimes for which there is no proof. Similarly, we do not restrain people’s liberties based on future conduct that has not yet occurred. SORNA, as written, does both of these things.”

In examining the second prong of this presumption, namely, the irrebuttable presumption is unconstitutional is the presumption is not universally true, the defense relied on the testimony of Dr. Karl Hanson, Dr. Elizabeth Letourneau, with a third expert, Dr. James Presscott present to testify to the efficacy of SORNA. All three are recognized experts in the field of sex offenses and recidivism. Letourneau and Hanson had testified that recidivism rates are extremely low (between 80%-95% will not reoffend sexually, and that about 95% of sex cries are committed by first-time offenders.

In response to the defense experts, the Commonwealth presented the expert report and testimony of Dr. Richard McCleary, Ph.D. McClearly is a professor at UC-Irvine, which helped publish the Scurich and John study. The court found McCleary and his reliance of the Scurich and John study unreliable and Dr. McCleary to be less than fully credible. 

“Dr. McCleary’s report in large part attacked the methodology of all of the research showing a low rate of sexual reoffending by SOs or otherwise showing the inefficacy of SORNA’s registration and notification requirements. In other words, Dr. McCleary opined that all research yielding an outcome different from that of the Commonwealth’s position has fatally methodologically flawed and unreliable. Dr. McCleary’s blanket denunciation of all research contrary to the Commonwealth’s position in this case, in our opinion, materially detracts from his credibility.”

“The research discussed by Drs. Hanson, Letourneau, and Prescott was conducted by well-respected experts in the field, including, but not limited to, Drs. Hanson, Letourneau, and Prescott’s own research. As Dr. Hanson noted, ‘There is no study that is perfect. Studies are not like that. . . . Almost all studies can be improved in particular ways.’ This is why studies are peer-reviewed and subject to the efforts of other researchers to replicate their results. As all studies have flaws that can be improved upon by further research, Dr. McCleary’s criticism of the science opposing the Commonwealth’s position can be applied with equal fervor to the studies cited by the Commonwealth in support of its position, suggesting de facto that we can rely on none of the scholarship in this area of the law, a proposition that is inimical to both common sense and the obligations of the judiciary. We are not persuaded by Dr. McCleary’s opinion that the pitfalls endemic to the human component of science render all of the research critical of SORNA unreliable and untrustworthy.”

The Court noted that both the Commonwealth and defense discussed the Scurich and John study. “Dr. Prescott testified that Scurich and John used a set of hypotheticals based on only four (4) studies and made assumptions with respect to the values of the variables used to measure the data from these four (4) studies, thereby allowing differing results based upon the assumptions employed.”

As Dr. Hanson testified, “There are no findings in that study. It is a statistical based on certain assumptions. If you follow those assumptions, you get that result. I do not agree with the assumptions. They [sic] are two fundamental areas of disagreement.”

“Their model assumes recidivism risk is a constant that does not change over time. This assumption is not supported by the data. Recidivism does change over time.”

“They also assume that most individuals who do reoffend do so rarely, once. in a while. They also have no category for no recidivism. So they don’t create a category of people who do not reoffend, so to speak.”

“So if you look at the undetected rates, think about three groups. So going forward-you can have three behaviors:”

“One, you cannot reoffend. That’s one. You can just not reoffend and you wouldn’t influence the recidivism statistics because you are not reoffending.
If you offend a lot, if you do it again and again and again, even if the detection rate for offense is low eventually you will get caught. You will just keep going. If you offend once in a while, like once every 5 years or once every 10 years or just once, you may or may not get caught. And it’s that group that is moving that undetected figure.”

“So if that group of low rate offenders is large, most of them, then you will get numbers like the ones. Scurich and John have. If that group is small, you will get numbers that are very close to the observed number.”

“We don’t know how big that is. It could be middle, small, or big. And because we don’t know that number we do know that the observed rates underestimate the .true rates, but we don’t know how much. We don’t know by how much.”

“Scurich and John make an implication. They do not directly state it and they do not support in that their assumptions are correct, but they make the implication that the recidivism rates are very, very high. That would not be generally accepted in the professional community, scientific community.”

The Court then noted this co-called “dark figure” is merely speculative, there is no hard evience to support it, and that there is no evidence that unreported crimes (which exist for all offenses) are somehow uniquely higher among sex crimes than other offenses. The court concluded that recidivism has been proven to be exteemely low, thus debunking the state’s assumption that ‘all sex offenders pose a high risk.”


Because there is no way to effectively evaluate unreported incidents even with the National Crime Victimization sample size of 70k to 100k, victim advocate groups have been free to make unfounded claims of widespread underreporting. But the few studies that have tried to address underreporting suggest that most unreported incidents were seen even by survey takers as incidents that either was not a crime or was considered not worth reporting for various reasons.

The dominant narrative about underreporting can be debunked by dispelling logical fallacies proponents of the underreporting myth employ. Proponents of the underreporting myth state there is no way to dispel their statements; in reality, there is also no way to verify their statements are true. The primary tactic of proponents of the underreporting myth relies on biases against those on the registry to lead people to their desired results. Proponents must rely on controversial studies like the Prentky, Langevin, Ahlmeyer, and Abel studies, i.e., a few studies that have claims of high levels of re-offense among people convicted of sex crimes.

To combat the myth of underreporting, you must be aware of arguments utilizing a number of logical fallacies. Any narrative minimizing false allegations and reports relying on tactics like polygraphs or self-reporting from people who are in a setting where rewards for cooperation are given should be challenged. Such narratives are meant to lead people into accepting the belief of widespread underreporting of sex crimes. Proponents of the underreporting myth often have vested interests in spreading suggestions of underreporting at epidemic levels. Most importantly, remember that few studies have studies the topic of sex offense underreporting, but fewer have given the reasons for underreporting.


  1. Aljumily, Refat, Quantitative Criminology: Bayesian Statistics for Measuring the ‘Dark Figure’ of Crime (July 4, 2017). Online at SSRN: or
  2. “Argument from Ignorance.” Logically Fallacious. Online at
  3. See TCR Staff, “Measuring the ‘Dark Figure’ of Crime.” The Crime Report. 28 July 2017. Online at
  4. Roger Przybylski. “Chapter 5: Adult Sex Offender Recidivism.” SOMAPI. Online at
  5. “Data Collection: National Crime Victimization Survey (NCVS).” Online at
  6. A sample of the survey form is at
  7. “CRIMINAL VICTIMIZATION, 2017.” BJS. Dec. 2018. p.20. Online at
  8. “Criminal Victimization, 2010.” BJS, Sept 2011. p.14. Online at
  9. See Tony Gonzalez. “Study: Sexual assaults greatly underreported.” USA Today. 19 Nov 2013. Online at , “The Nashville Sexual Assault Center, for example, reported an increase in the number of people stepping forward to report sexual abuse, attributed in part to intense coverage of former Penn State University assistant football coach Jerry Sandusky, convicted of 45 counts of child sex abuse involving 10 boys.”
  10. “Rape and Sexual Assault.” Bureau of Justice Statistics. Online at
  11. S.H.G. “Stare Rape Is Now Official, Honestly.” Simple Justice: A Criminal Defense Blog. 26 Dec. 2018. Online at
  12. Dave Choate. “Bill Toughens Law on Visual Sexual Aggression Against Children in Maine.” Seacoast Online. 6Apr 2008. Online at
  13. Cathy Young. “Feminists want us to define these ugly sexual encounters as rape. Don’t let them.” Washington Post. 20 May 2015. Online at
  14. Caitlin Nolan. “Rape by Fraud: Inside the Fight to Criminalize Lying About Who You Are to Sleep With Someone.” Inside Edition. 12 Dec. 2018. Online at
  15. Cydney Adams. “Can drunk sex ever be consensual?” CBS News, 26 Apr 2019. Online at
  16. Ashe Schow. “Ever had drunk sex? That’s rape, according to this university.” Washington Examiner. 22 July 2015.  Online at
  17. From, published 2017. Online at
  18. “Girl Thinks If You Regret Having Sex It Means You’ve Been Raped, Gets A Perfect Lesson On Consent.” Bored Panda. 2018. Online at
  19. “Sexual Assault of Young Children as Reported to Law Enforcement: Victim, Incident, and Offender Characteristics.” US Dept. of Justice. 2000. Online at
  20. See “Get Statistics.” National Sexual Violence Resource Center. 2018. Online at
  21. See Derek Logue, “False Allegations.” OnceFallen, 12 Dec 2009. Online at
  22. Andrew J. R. Harris and R. Karl Hanson. “Sex Offender Recidivism: A Simple Question.” Public Safety and Emergency Preparedness Canada. Online at
  23. “Criminal Victimization in the United States, 2008 – Statistical Tables.” Bureau of Justice Statistics. 2010. Online at
  24. “Criminal Victimization in the United States, 2005 – Statistical Tables.” Bureau of Justice Statistics. 2006. Online at
  25. Patkin, Debra. “Megan’s law and the misconception of sex offender recidivism.” 2008. <>
  26. See Jeffrey C. Sandler, Naomi J. Freeman, and Kelly M. Socia. “DOES A WATCHED POT BOIL? A Time-Series Analysis of New York State’s Sex Offender Registration and Notification Law.” Psychology Public Policy and Law 14(4):284-302 • November 2008. Online at’s_Sex_Offender_Registration_and_Notification_Law
  27. Derek Logue. “Recidivism: The Great Lie of “Frightening and High”. Once Fallen. 8 Aug 2018. Online at  http://www.
  28. Supra., Przybylski
  29. Scurich, Nicholas and John, Richard S., The Dark Figure of Sexual Recidivism (February 4, 2019). UC Irvine School of Law Research Paper No. 2019-09. Available at SSRN:
  30. Prentky, R. A., Knight, R. A., & Lee, A. F. S.” Child sexual molestation: Research issues.” Research Report, National Institute of Justice, Washington, DC. June 1997Online at
  31. Supra., Przybylski
  32. Ron Langevin, Suzanne Curnoe, Paul Fedoroff, Renee, Mara Langevin, Cheryl Peever, Rick Pettica, and Shameen Sandhu. “Lifetime Sex Offender Recidivism: A 25-Year Follow-Up Study.” Canadian Journal of Criminology and Criminal Justice, Vol. 46, No. 5. DOI: 10.3138/cjccj.46.5.531 (2004)
  33. Sean Ahlmeyer, Peggy Heil, Bonita McKee, & Kim English. “The Impact of Polygraphy on Admissions of Victims and Offenses in Adult Sexual Offenders.” Sexual Abuse: A Journal of Research and Treatment. April 2000, Volume 12, Issue 2, pp 123–138
  34. Gene Abel et al., “Self-Reported Sex Crimes of Non-Incarcerated Paraphiliacs,” Journal of Interpersonal Violence (1987), pp. 3-25
  35. Supra., Przybylski
  36. Hanson, R.K. & Morton-Bourgon, K.. “Predictors of Sexual Recidivism: An Updated Meta-Analysis.” Ottawa, ON: Public Safety and Emergency Preparedness Canada. 2004.
  37. Canada’s age of consent raised by 2 years”. CBC News. 1 May 2008. Online at
  38. Supra., Scurich and John, “Dark Figure”
  39. Lave, Tamara R. “The Problem with Assumptions: Revisiting “The Dark Figure of Sexual Recidivism”.” J.J. Prescott and Grady Bridges, co-authors Behavioral Sciences & the Law 39, no. 3 (2020): 279-306.
  40. Ibid.
  41. “From Rage to Reason: Why We Need Sex Crime Laws Based on Facts, Not Fear.” Emily Horowitz, Praeger Publishers, 2023. Page 66