Melissa Hamilton

Dr Melissa Hamilton

Reader in Law and Criminal Justice
+44 (0)1483 682827
04 AB 05


Research interests

Interdisciplinary research on issues related to domestic and sexual violence, trauma responses in victims of assault, risk assessment practices, policing, sentencing, and corrections.


Criminal Justice

Domestic Violence & the Law


State Bar of Texas

American Psychological Association

American Psychology-Law Association

Institute on Domestic Violence and Sexual Assault

International Corrections and Prisons Association

Risk Assessment Task Force, National Association of Criminal Defense Lawyers

Royal Statistical Society

My publications


Hamilton M (2012) The child pornography crusade and its net-widening effect,Cardozo Law Review 33 (4) pp. 1679-1732 Yeshiva University
Hamilton M (2016) Some facts about life: The law, theory, and practice of life sentences.,Lewis & Clark Law Review 20 (3) pp. 803-855 Lewis & Clark Law School
A diverse band of politicians, justice officials, and academic commentators
are lending their voices to the hot topic of correcting the United
States? status as the world?s leader in mass incarceration. There is limited
focus, though, upon the special role that life sentences play in explaining
the explosion in prison populations and the dramatic rise in costs that
result from providing for the increased needs of aging lifers. This Article
highlights various ways in which those serving life sentences occupy
unique legal and political statuses. For instance, life sentences are akin
to capital punishment in likely resulting in death within prison environs,
yet enjoy few of the added procedural rights and intensity of review
that capital defendants command. In contrast to term prisoners, lifers
cannot expect to reenter civil society and thus represent an exclusionist
ideological agenda. The Article reviews whether life penalties remain justified
by fundamental theories of punishment in light of new evidence on
retributive values, deterrence effects, and recidivism risk. It also situates
life sentences within an international moral imperative that reserves life
penalties, if permitted at all, for the most heinous offenders, and in any
event, demands periodic review of all long-term prison sentences.
This Article also provides a novel perspective by presenting an empirical
study to further investigate the law and practice of life sentences. Utilizing
federal datasets, descriptive statistics, and a multiple regression
analysis offers important insights. The study makes an original contribution
to the literature by exploring the salience of certain facts and circumstances
(including demographic, offense-related, and case-processing variables)
in accounting for life sentence outcomes in the federal system.
While some of the attributes of life sentenced defendants are consistent
with current expectations, others might be surprising. For example, as expected,
sentencing guideline recommendations, the presence of mandatory
minimums, and greater criminal history predicted life sentences. Results
also supported the existence of a trial penalty. On the other hand, lifers
in the federal system were not representative of the most violent offenders or worst recidivists. Life sentences were issued across a variety of violent
and nonviolent crimes, and in recent years a substantial percentage presented
with minimal criminal histories. Regional disparities in the use of
life sentences were also indicated. In concluding, this Article reviews potential
remedies to the overreliance upon life penalties in the American
justice system.
Hamilton M (2013) Adjudicating Sex Crimes as Mental Disease,Pace Law Review 33 (2) pp. 536-599 Pace University School of Law
Hamilton M (2010) Judicial discourses on women's agency in violent relationships: Cases
from California
Women's Studies International Forum 33 (6) pp. 570-578 Elsevier
Adult female targets of domestic violence by male perpetrators have commonly been described
as helpless and passive. This is consistent with the criminal justice system's perception that
true ?victims? have little culpability or agency in a violent assault. Otherwise, the ?victims? are
more likely to be defined as participants in the violent act, and thus unworthy of official
protection. This study examines court opinions involving convictions of male offenders of
domestic violence against their female partners and ex-partners. The purpose is to understand
the development of judicial knowledge as to whether women in relationships with violent men
are socially constructed as worthy and legitimate victims of violence. The 60+ appellate case
opinions in the analysis are those where a California trial court accepted expert testimony on
domestic violence in prosecuting the male offenders to explain the women's actions regarding
their violent relationships. California was chosen because of the state's progressive and unique
evidentiary statutes that permit a broad range of evidence in criminal prosecutions of domestic
violence, including expert witnesses. In reviewing the judicial opinions that comprise the
corpus, I found that an underlying assumption evident in the judicial discourses is that abused
women would, should or could easily exercise agency in ending an abusive relationship and,
once it was ended, refuse to reengage in their abusive relationships. Using critical discourse
analysis, this study shows that, in constructing women's agency in resisting abusive
relationships, judicial discourse tended to rely more heavily upon expert testimony and, in a
few cases, on prosecutorial arguments, than on the testimony (i.e. voice) of the female victims
themselves. In this process, the women's voices were silenced or marginalized as experts?
constructions of victimized women were preferred.
Hamilton M (2011) Reinvigorating Actus Reus:The Case for Involuntary Actions
by Veterans with Post-Traumatic Stress Disorder
Berkeley Journal of Criminal Law 16 (2) pp. 340-390 Berkeley Journal of Criminal Law
Matthew Sepi, a 20-year-old combat veteran who had been
deployed in Iraq, headed out to a local convenience store in Las Vegas in
2005 concealing an AK-47 under his clothing in case it was necessary to
protect himself in the neighborhood that was known for violence and
crime.' At one point a man and a woman approached him in a dark alley,
ordering Sepi to leave the area. Feeling he was being ambushed by enemy
troops, Sepi instinctively reacted by "engag[ing] his targets" and shooting
at them. Once the individuals appeared immobilized from the gunshots,
Sepi followed training protocol in "breaking contact" with the enemies
and retreating. Both individuals were shot and one of them died of
gunshot wounds. Sepi was charged with murder and attempted murder.
Hamilton M (2015) The reliability of assault victims' immediate accounts: evidence from trauma studies,Stanford Law & Policy Review 26 (1) pp. 269-306 Stanford Law School
The admission of hearsay qualifying as an excited utterance, present sense
impression, or statement about mental and bodily conditions is an exception to
the general rule of inadmissibility for hearsay statements. Evidence scholars explain
these exceptions as being presumably reliable statements as they are generally
contemporaneous with an event at issue such that faults with memory and
time to lie are remedied. These three exceptions have been particularly depended
upon in cases of interpersonal violence in which victims are considered to honestly
complain during the occurrence of the assault and in its immediate aftermath.
Nonetheless, much recent research in interdisciplinary circles highlights
that the impact of trauma has varied consequences upon subjects' abilities to accurately
and fully articulate what just transpired. Concurrent neurophysiological
reactions to traumatic stress can mediate, alter, or entirely thwart one's capacity
to conceptualize internally, and to clearly verbalize externally, the violent attack.
Thus, unlike the hearsay exceptions' presumption of accuracy, a surfeit of scientific
knowledge now shows that violence victims may-or may not-issue holistic
and reliable reports in the near term. On the other hand, empirical studies reject
the notion that it takes more than a blink of an eye to fabricate a story.
Evidence law is often intransigent in its reliance upon folk psychological assumptions
about human behavior. Yet with legal scholars and practitioners increasingly
embracing the benefits that scientific knowledge can bring to the law,
the time may be ripe to reconsider these three hearsay exceptions. In light of recent
studies drawing from neurology, physiology, and psychology principles and
research designs in trauma studies, the goal of evidence law in terms of preventing
unreliable testimony can only benefit thereby.
Hamilton M (2015) Risk-needs assessment: constitutional and ethical challenges,American Criminal Law Review 52 pp. 231-291 American Criminal Law Review
... Part V offers a review of case law involving the role of the two actuarial assessment tools in SVP status cases,
including an assessment of how courts have responded to Daubert-and Frye-based challenges to the instruments. ...
Hence, with the Supreme Court's approval of expert predictions of future violence in death penalty cases, and with the
majority's reference to expert assessments of the risk of violence in civil commitments, it seems reasonable to
extrapolate Barefoot's general conclusion to future dangerousness assessments of sex offenders. ... To develop the
experience table, the developer used the sexual recidivism rates observed in seven follow-up studies of released sex
offenders in the United States, Canada, and England. ... The STATIC-99 instrument includes 10 static factors : Age at
assessment: Number of prior sentencing 0 = 25 years or older dates: 1 = between 18 and 25 years 0 = 3 or less 1 = 4 or
more Having lived with an age-appropriate Any convictions for a non- intimate partner for at least 2 years: contact
sexual offense: 0 = yes; 1 = no 0 = no; 1 = yes Any convictions for an Index non-sexual Any nonfamilial victims:
violent offense: 0 = no; 1 = yes 1 = yes; 0 = no Any convictions for non-sexual violence Any stranger victims: before
the Index (most recent sexual 0= no; 1 = yes offense) offense: 1 = yes; 0 = no Number of prior sex offenses: Any male
victims: 0 = none 0 = no; 1 = yes 1 = 1-2 charges or 1 conviction 2 = 3-5 charges or 2-3 convictions 3 = > 6 charges or
> 4 convictions For STATIC-99, total scores range from 0 to 12, arranged within seven risk categories organized into
four ordinal risk groups (from 0 = low risk to 6+ = high risk). ... It is highly questionable whether there ever was - and
even more questionable whether there is today - a general acceptance in the mental health field about the validity of
using actuarial risk assessments in SVP legal determinations. ... Judicial Perspectives on Future Dangerousness
Evidence Since the Supreme Court approved mental health testimony about future dangerousness and found civil
commitment of sexual predators and registration laws to be constitutional, the introduction of actuarial risk assessments
through expert testimony has become common practice in SVP determinations. ... In the case, the prosecutor had
argued that even low scores from actuarial tools are sufficient to constitute the legal standard of "likely" to reoffend:
Even taking the expert's tests, the RRASOR, about
Hamilton M (2011) The Efficacy of Severe Child Pornography Sentencing: Empirical Validity or Political Rhetoric?,Stanford Law & Policy Review 22 (2) pp. 545-586 Stanford Law School
Congress continues to push for harsher sentencings for child pornography cases, likely due to the polarizing opinion that those convicted of this offense perhaps are or will become child molesters. However, federal judges are more often of the opinion that the sentencing guidelines are too severe and do not provide flexibility depending on the case specifics. This Article first contextualizes the history of the sentencing expansions and discusses cases that raise different issues on both sides of the argument.
Hamilton M, Worthen M (2010) Sex Disparities in Arrest Outcomes for Domestic Violence,Journal of Interpersonal Violence 26 (8) pp. 1559-1578 Sage
Domestic violence arrests have been historically focused on protecting
women and children from abusive men. Arrest patterns continue to reflect
this bias with more men arrested for domestic violence compared to women.
Such potential gender variations in arrest patterns pave the way to the
investigation of disparities by sex of the offender in domestic violence arrests.
This study utilizes data from a quantitative dataset that includes responses by
police officers who completed a specially mandated checklist after responding
to a domestic dispute. The results showed that while females are arrested
quite often in domestic disputes, there remains a significant difference in the
arrest outcome whereby male suspects were more likely to be arrested than
female suspects. Regression models further indicated differences based on
sex and certain predictors of arrest, which supported sex-based rationales in
arrests for domestic violence.
Hamilton M (2017) Constitutional law and the role of scientific evidence: the transformative potential of Doe v. Snyder,Boston College Law Review E Supp. 58 (E Supp) Boston College
In late 2016, U.S. Court of Appeals for the Sixth Circuit?s concluded in Does #1?5 v. Snyder that Michigan?s sex offender registry and residency re-striction law constituted an ex post facto punishment in violation of the constitu-tion. In its decision, the Sixth Circuit engaged with scientific evidence that re-futes moralized judgments about sex offenders, specifically that they pose a unique and substantial risk of recidivism. This Essay is intended to highlight the importance of Snyder as an example of the appropriate use of scientific studies in constitutional law.
Hamilton M (2016) Political and Empirical Controversies
Threaten the Federal Child Pornography
In: Hessick C (eds.), Refining Child Pornography Law: Crime, Language, and Social Consequences pp. 261-283 University of Michigan Press
Hamilton M (2014) McSentencing: Mass Federal Sentencing and the Law of Unintended Consequences,Cardozo Law Review 35 (6) pp. 2199-2262 Yeshiva University
Hamilton M (2014) Prison-by-default: challenging the federal sentencing policy's presumption of incarceration,Houston Law Review 51 (5) pp. 1271-1334 Houston Law Review
The United States has earned its nickname as a mass incarceration nation. The federal criminal justice system has contributed to this status with its own increasing rate of incarceration. The federal system now ranks as the largest population of sentenced prisoners in the country; it is even larger than the national prisoner populations among all European countries, save one. This is a recent phenomenon. This Article ties the increase in the federal incarceration rate to policies adopted by the U.S. Sentencing Commission since its inception that presume imprisonment as the default sentence. Since the Sentencing Commission?s creation in 1984, the proportion of federal sentences requiring incarceration increased from under 50% to over 90%. This Article provides evidence that the prison-by-default position by the Sentencing Commission is contrary to congressional intent when the Legislature passed sentencing reform laws in the 1980s, has contributed to a federal prison system that is operating over capacity, and wastes resources. The increasing rate of imprisonment at the federal level conflicts with the downward trend in national crime rates and with the states? sentencing experiences in which probation sentences continue to be preferred. Potential alternative explanations for the significant trend toward the affirmative use of imprisonment in federal sentences are outlined, yet the available statistical evidence generally rules them out. Finally, suggestions on changes to the sentencing guidelines and to judicial sentencing practices are offered.
Hamilton M (2017) Excessive lethal force,Northwestern University Law Review 111 (4) pp. 155-171
In this Essay, Professor Hamilton considers the recent use by Dallas police officers of a robot armed with plastic explosives to kill a suspected gunman on a shooting rampage. In the wake of Dallas, many legal experts in the news maintained that the police action was constitutional. The commentators' consensus was that as long as the police had the right to use lethal force, then the means of that force is irrelevant. This Essay argues the contrary. Under the current state of the constitutional law on the police use of force on a suspected felon, excessive lethal force is a valid consideration. The type and magnitude of lethal force may, under certain circumstances, be unconstitutional despite the suspect posing a high degree of risk to others.
Hamilton M (2016) Police robots and the law,Westlaw Journal Computer & Internet 34 (5) pp. 3-5 Thompson Reuters
On July 7 Dallas officials used a robot to kill
the suspected shooter of five police officers.
The homicide of the suspect was precipitated
by a series of events.
After a prolonged gun battle and hours of
negotiations with police, the suspect, then
holed up in a confined area of a college
building, continued to threaten to kill more
and claimed to have planted bombs nearby.
Investigating officers decided the time
had come to incapacitate him. The police
secured a one-pound chunk of C4 plastic
explosive material to the extendable arm of
a militarized robot. Then, they sent the robot
into the confined area where the suspect was
concealing himself.
The police officer operating the robot
remotely blew up the attached explosive, and
as intended, the suspect was immediately
killed. This is believed to be the first time in
domestic policing that a robot carried out an
act of lethal force.
Hamilton M (2016) Extreme prison sentences: Legal and normative consequences,Cardozo Law Review 38 (1) pp. 59-120 Yeshiva University
Hamilton M (2014) Sentencing Policy Disputes (Editorial Introduction),Criminology & Public Policy 13 (2) pp. 237-240 Wiley
Last year, Blomberg,Mestre, andMann (2013) in Criminology & Public Policy called
on criminologists to embolden themselves to offer the best empirical research to
inform public policy discussions concerning criminal justice issues, even if their
research cannot show causality. The main research article in this segment represents a
wonderful example of such a contribution. Kaiser and Spohn?s (2014, this issue) research
directly confronts an area of criminal justice in current turmoil because of doctrinal and
moral policy disputes. The realm is the federal sentencing system. Created by Congress
in the Sentencing Reform Act of 1984, the U.S. Sentencing Commission was tasked with
the responsibility of establishing presumptive sentencing guidelines to direct sentencing
judges in determining a reasonable sentence. A goal of the reform legislation was to foster
consistency in sentencing practices and thereby reduce unwarranted disparities. Yet the
U.S. Supreme Court untethered the presumptive sentencing guideline regime in the case
of United States v. Booker in 2005 when it remedied a constitutional error it found plagued
the guideline structure by rendering the guideline system advisory in nature. Federal district
judges were given further leeway when the Supreme Court in Kimbrough v. United
States (2007) ruled the judiciary could reject guideline recommendations based on a policy
disagreement. Tension has existed ever since these rulings in terms of a power struggle for
determining reasonable punishments, spawning discussions and debates among researchers,
academics, practitioners, and policy makers about how to repair the discord and, perhaps
more importantly, meliorate policies...
Hamilton M (2015) Adventures in risk: Predicting Violent and
Sexual Recidivism in Sentencing Law
Arizona State Law Journal 47 (1) pp. 1-62 Arizona State University College of Law
A new arena inviting collaboration between the law and sciences has emerged in criminal justice. The nation?s economic struggles and its record-breaking rate of incarceration have encouraged policymakers to embrace a new penology which seeks to simultaneously curb prison populations, reduce recidivism, and improve public safety. The new penology draws upon the behavioral sciences for techniques to identify and classify individuals based on their potential future risk and for current best evidence to inform decisions on how to manage offender populations accordingly. Empirically driven practices have been utilized in many criminal justice contexts for years, yet have historically remained ?a largely untapped resource? in sentencing decisions. One reason is that sentencing law in America has for some time been largely driven by retributive theories.The new penology clearly incorporates utilitarian goals and welcomes an interdisciplinary approach to meet them.
The Supreme Court may soon hear a case on data-driven criminal sentencing. Research suggests that algorithms are not as good as we think they are at making these decisions.
Hamilton Melissa (2017) Briefing the Supreme Court: promoting science or myth?,Emory Law Journal Online 67 pp. 2021-2043 Emory Law Journal
The Supreme Court will soon decide if North Carolina?s ban on the use
of social networking websites by registered sex offenders is constitutional.1
The case is Packingham v. North Carolina and oral arguments were heard in
February 2017. The principal legal issue in the case is whether the ban
violates the First Amendment?s right to freedom of speech.
Hamilton M (2017) Sentencing Disparities,British Journal of American Legal Studies 6 (2) pp. 179-224 De Gruyter Open

Criminal justice stakeholders are strongly concerned with disparities in penalty outcomes.
Disparities are problematic when they represent unfounded differences in sentences,
an abuse of discretion, and/or potential discrimination based on sociodemographic
characteristics. The Article presents an original empirical study that explores
disparities in sentences at two levels: the individual case level and the regional level.
More specifically, the study investigates upward departures in the United States? federal
sentencing system, which constitutes a guidelines-based structure. Upward departures
carry unique consequences to individuals and their effects on the system as they lead
to lengthier sentences, symbolically represent a dispute with the guidelines advice, and
contribute to mass incarceration. Upward departures are discretionary to district courts
and thus may lead to disparities in sentencing in which otherwise seemingly like
offenders receive dissimilar sentences, in part because of the tendency of their assigned
judges to depart upward (or not).

The study utilizes a multilevel mixed model to test the effects of a host of explanatory
factors on the issuance of upward departures at the case level and whether those same
factors are significant at the group level-i.e., district courts-to determine the extent of
variation across districts. The explanatory variables tested include legal factors (e.g., final
offense level, criminal history, offense type), extralegal characteristics (e.g., gender,
race/ethnicity, citizenship), and case-processing variables (e.g., trial penalty, custody
status). The results indicate that various legal and nonlegal factors are relevant in individual
cases (representing individual differences) and signify that significant variations
across district courts exist (confirming regional disparities). Implications of the significant
findings for the justice system are explored.

Hamilton Melissa (2019) The sexist algorithm,Behavioral Sciences & the Law 37 (2) pp. 145-157 John Wiley & Sons Ltd
Algorithmic risk assessment tools are informed by scientific research concerning which factors are predictive of recidivism and thus support the evidence?based practice movement in criminal justice. Automated assessments of individualized risk (low, medium, high) permit officials to make more effective management decisions. Computer-generated algorithms appear to be objective and neutral. But are these algorithms actually fair? The focus herein is on gender equity. Studies confirm that women typically have far lower recidivism rates than men. This differential raises the question of how well algorithmic outcomes fare in terms of predictive parity by gender. This essay reports original research using a large dataset of offenders who were scored on the popular risk assessment tool COMPAS. Findings indicate that COMPAS performs reasonably well at discriminating between recidivists and non?recidivists for men and women. Nonetheless, COMPAS algorithmic outcomes systemically overclassify women in higher risk groupings. Multiple measures of algorithmic equity and predictive accuracy are provided to support the conclusion that this algorithm is sexist.
Hamilton Melissa (2019) Debating Algorithmic Fairness,UC Davis Law Review Online 52 (4) pp. 261-296 University of California - Davis
Hamilton Melissa (2018) A THREAT ASSESSMENT FRAMEWORK FOR LONE-ACTOR TERRORISTS,Florida Law Review 70 (6) pp. 1319-1356 University of Florida Levin College of Law.
Lone-actor terrorist attacks are on the rise in the Western world in terms of numbers and severity. Public officials are eager for an evidence-based tool to assess the risk that individuals pose for terroristic involvement. Yet actuarial models of risk validated for ordinary criminal violence are unsuitable to terrorism. Lone-actor terrorists vary dramatically in their socio-psychological profiles and the base rate of terrorism is too low for actuarial modeling to achieve statistical significance. This Article proposes a new conceptual model for the terroristic threat assessment of individuals. Unlike risk assessment that is founded upon numerical probabilities, this threat assessment considers possibilistic thinking and considers the often idiosyncratic ideologies and strategies of lone-actor terrorists.

The conceptual threat assessment model connects three overlapping foundations: (a) structured professional judgment concerning an individual?s goals, capabilities, and susceptibility to extremist thought, plus the imminence of a potential terroristic attack; (b) a multidisciplinary intelligence team engaging collective imaginaries of an otherwise unknown future of terrorism events; and (c) coordination between counterintelligence officials and academic communities to share data and conduct more research on lone-actor terrorists utilizing a systematic case study approach and engaging theoretical methodologies to inform about potential new ideological motivations and terroristic strategies which may be emerging due to cultural, environmental, and political drivers.

Hamilton Melissa (2019) THE BIASED ALGORITHM: EVIDENCE OF DISPARATE IMPACT ON HISPANICS,American Criminal Law Review 56 (4) Georgetown University Law Center