This module is a resource for lecturers  


The Role of the Criminal Justice System


The obligations placed on States by the Protocol against Trafficking in Persons, particularly those under article 5, necessitate the use of domestic criminal justice systems and measures to prevent and combat trafficking. Those persons that commit the crime of trafficking in persons, as defined in the Protocol, must be subject to criminal offences under domestic law. In this way, criminal justice systems are responsive to trafficking, insofar as they are the avenue through which those offenders can be punished. However, criminal justice systems can also play an effective, pre-emptive, role in responding to trafficking, by preventing further commission of the crime and reducing overall levels of offending. Prevention is one of the purposes of the Protocol against Trafficking in Persons.

Importantly, insofar as criminal justice systems play a role in combatting and preventing trafficking in persons, this role must be implemented in a way that takes into account the protection needs of victims and fully respects their human rights. Criminal justice and human rights-based approaches to trafficking must be seen as complementary and mutually reinforcing. The rights of victims are explored below.


Prosecution as a prevention strategy

Put simply, trafficking in persons is a crime committed by offenders. As such, an appropriate and effective response to prevent trafficking is the prosecution and punishment of offenders. This has the dual effect of removing offenders from the community and deterring others from committing the crime. The primary motivation of offenders is often to profit from the exploitation of their victims. If they are exposed to the significant and timely risk of prosecution, lengthy jail sentences and forfeiture of their profits, this contributes to a reduction in the incidence of offending.

The role of the criminal justice system in combatting trafficking in persons is acknowledged by Governments, United Nations agencies, NGOs and academics, and is supported by established principles of criminology. For example, in its 2014 Global Report on Trafficking in Persons, UNODC (2014a) stated that:

"It is equally clear that without robust criminal justice responses, human trafficking will remain a low-risk, high profit activity for criminals."

Similarly, in its 2016 Global Report on Trafficking in Persons, UNODC (2016) observed:

"Unfortunately, the average number of convictions remains low. UNODC's findings show that there is a close correlation between the length of time the trafficking law has been on the statute books and the conviction rate. This is a sign that it takes time, as well as resources, and expertise to chase down the criminals. Perhaps the 2016 Report's main message is that inroads have been made into this horrendous crime. We must, however, continue to generate much needed cooperation and collaboration at the international level, and the necessary law enforcement skills at the national and regional levels to detect, investigate and successfully prosecute cases of trafficking in persons".

Findings from the 2018 Global Report on Trafficking in Persons also confirm a correlation between increased institutional responses with an increase in number of convictions (UNODC, 2018).

The Human Rights First 2017 report entitled "How to Disrupt the Business of Human Trafficking" highlights:

"A shift must occur to change the equation for traffickers. The focus must be on disrupting the business of human trafficking. Experts agree that human trafficking must be fought on several fronts, including providing more reliable data, improving prosecutions, increasing the cost and risk of trafficking to the perpetrators and enablers, strengthening partnerships with allies in private industry ... Prosecutions of human trafficking must target all individuals involved in this criminal business. Law enforcement and prosecutors must achieve this objective by employing enhanced expertise, adopting a victim-centred approach, and with increased access to tools enhancing investigations and prosecutions".

Deterrence is traditionally a central component of criminal punishment, achieved through the imposition of penalties on offenders. In the context of trafficking in persons, the goal is to deter both the offender from future offending, as well as the general population from commission of the crime (referred to respectively as "specific" and "general" deterrence) (see Beyleveld, 1979 for an overview of the concept). Deterrence is just one of several common objectives for the punishment of criminal offenders. Others include:

  • Just punishment of the offender (proportionately to the gravity of their offending).
  • Rehabilitation of the offender (to prevent recidivism and reform the offender).
  • Community protection.
  • Compensation of victims.

By way of example, section 142 of the United Kingdom Criminal Justice Act 2003 provides:

Purposes of sentencing

(1) Any court dealing with an offender in respect of his offence must have regard to the following purposes of sentencing:

(a) the punishment of offenders,

(b) the reduction of crime (including its reduction by deterrence),

(c) the reform and rehabilitation of offenders,

(d) the protection of the public, and

(e) the making of reparation by offenders to persons affected by their offences.

Nonetheless, the efficacy of deterrence, both specific and general, has been extensively questioned by experts. It is a controversial topic and often the subject of considerable disagreement (see, eg, Bagaric and Alexander, 2012). In particular, the effectiveness of harsher punishments on future offending has been frequently tested and questioned.

Rather than a narrow focus on deterrence and punishment, criminal justice responses to trafficking in persons should ideally encompass a broader range of crime prevention strategies. These include approaches designed to strengthen communities and address structural factors that lead to trafficking. Such factors include socio-economic deprivation, inequality, conflict and post-conflict settings, discrimination and persecution. This accords with the UN's Sustainable Development Goal 16, which calls for the promotion of peaceful and inclusive societies, access to justice for all, and accountable and inclusive institutions.


Roles of criminal justice actors

States' criminal justice systems encompass a broad range of actors and institutions. This section gives an overview of the roles of some key criminal justice actors involved in the prosecution of traffickers, including prosecutors, defense lawyers, police and the judiciary. Police forces also play an important role in crime prevention.


The responsibilities of prosecutors in relation to victims include (UNODC, 2014b; Council of Europe, 2017):

  • Cooperating with police to coordinate further investigations and strengthen the case against the accused (see also Module 14 "Independence of the Judiciary and the Role of Prosecutors" of the University Module Series on Crime Prevention and Criminal Justice).
  • Briefing their evidence in a victim sensitive manner and making an assessment as to whether to call them as a witness at trial. Ensuring that the victim statement is comprehensive, thereby getting information on all aspects of the crime.
  • Deciding whether there is sufficient evidence to prosecute the accused.
  • Choosing and constructing the charges against the accused.
  • Considering whether to oppose bail applications by the defendants if they are likely to abscond, or otherwise represent a threat to victims, witnesses or the integrity of the trial. In accordance with the UN Standard Minimum Rules for Non-Custodial Measures, pre-trial detention should only be used as a means of last resort.
  • Informing the victim of the procedures in court, how the witness is to address the judge and the lawyers, where they are to sit or stand when they give evidence and how they are to give their testimony.
  • Presenting evidence in a comprehensive and precise manner, including by citing case law, profiling the traffickers, emphasizing the grave nature of the crime of trafficking, linking the harm to the victims and demonstrating the organized nature of the crime, where relevant.
  • Preventing re-victimization by ensuring that the rights of the victim are protected at all stages of the trial process. This can be achieved by, inter alia, arranging a safe waiting area for victims and witnesses in the courthouse that separates them visually and audibly from the suspects. The rights of victims are further explored in a dedicated section of this module and in Module 11 "Justice for Victims" of the Criminal Justice and Crime Prevention University Modules Series.
  • Seeking court directions to protect the victim both before and after the hearing, including directions prohibiting the publication of the identity and location of victims and their families, vulnerable witness measures such as directions that victims and vulnerable witnesses give their evidence via video link or behind a screen, etc.
  • Where appropriate and proportionate to the gravity of offending, seeking increased sentences against the accused for any aggravating conduct.
  • Applying for compensation or reparation orders, if permitted by the law.

Defense lawyers

It is the role of defence lawyers to represent the accused before, during and after a trial, to conduct a competent defence and to protect the accused's rights under law. This includes seeking bail for their clients, where appropriate, and conducting their defence at trial and making a plea of mitigation at any sentencing hearing. As such, they will have the opportunity to cross-examine the victim and call evidence from other witnesses.

Although the defence counsel may conduct a robust cross-examination, he/she is not allowed to harass the witness or act in an overbearing, disrespectful or unfair manner (United Nations Congress on the Prevention of Crime and the Treatment of Offender, 1990). At all times, court proceedings must be conducted in a fair, humane and accountable manner cognisant of both the victim's and the accused's rights (see SDG 16 and the Preamble of the Doha Declaration).



The responsibilities of police in relation to the trial include presenting evidence for the prosecution, managing the security/protection of victims and other prosecution witnesses, and controlling offenders that are held in custody, including:

  • Maintaining custody of the accused.
  • Arranging security and protection if this is an issue.
  • Arranging a safe waiting area for victims and witnesses in the courthouse that separates them visually and audibly from the suspects.
  • Keeping the victim informed of developments, for example: when will the trial commence, have the traffickers applied for and been granted bail; what was the outcome of the trial; what sentences were imposed?


The responsibility of judges is to manage the criminal trial to ensure that it is just, fair and carried out in accordance with the law. If they fail to do so they risk an unfair trial, with the result that there may need to be a second trial at which victims will need to repeat their evidence. Alternatively, traffickers may go free where there is a successful appeal or no further prosecution following a mistrial. Judges have several duties, including:

  • Determining bail applications in accordance with the law.
  • Considering, and if appropriate, making vulnerable witness orders allowing vulnerable witnesses to give evidence by video conference or behind a screen.
  • Making appropriate orders and directions to protect witnesses from intimidation and abuse.
  • Ensuring that court interpreters are available if required.
  • Ensuring that the cross-examination of child witnesses and vulnerable victims is comprehensible and appropriate. In addition, judges must prohibit cross examination that is abusive, rude or threatening or which deals with matters of a personal and potentially embarrassing nature, which have little relevance or for which the prejudicial value outweighs the evidential value. That is, questions that cause stress, shame and embarrassment to the witness, but otherwise shed little light on the guilt or innocence of the accused.
  • Deciding points of law and ruling on procedural and evidentiary issues that arise.
  • In judge only trials, deciding the guilt of the accused. In jury trials, the judge must give directions to the jury before they retire to consider their verdict.
  • In both judge and jury trials, passing sentence on convicted offenders.
  • Considering applications for reparation or compensation orders in favour of victims (UNODC, 2007).

Sentencing of offenders

When trafficking offenders are prosecuted and found guilty, they should be punished appropriately by the State. Punishment is important as it shows that society disapproves of the conduct. While domestic anti-trafficking legislation should prescribe heavy penalties for trafficking in persons, concomitant with the seriousness of the crime, it may also provide for higher sentences where the accused's position or particularly egregious offending calls for them. Such aggravating circumstances can be divided into three general groups, depending on whether they pertain to the trafficking offender, the victim of trafficking or the act of trafficking itself (UNODC, 2008, pp. 43-44). Examples that may be found in domestic legislation include:


Aggravating circumstances pertaining to the offender

  • The offender is a member of a criminal organization;
  • The offender is a parent, sibling, guardian, spouse, partner or person exercising authority over the trafficked person;
  • The offender was in a position of responsibility or trust in relation to the victim;
  • The offender was in a position of authority or control or command of a child victim;
  • The offence was committed by a public official;
  • The offender has been previously convicted of the same or a similar offence;
  • The offender intended serious harm;
  • The offence was motivated by financial or material gain;
  • Deliberate attempts were made to obstruct justice;
  • The offence involved planning and deliberation.

Aggravating circumstances pertaining to the victim

  • The offence has deliberately or by gross negligence endangered the life of the victim;
  • The offence has caused the victim's death or suicide;
  • The offence has caused particularly serious harm or bodily injuries to the victim and psychological and physical diseases, including HIV/AIDS;
  • The offence has been committed against a victim who was particularly vulnerable, including a pregnant woman;
  • The trafficked person is a child;
  • The trafficked person is a person with a physical or mental disability;
  • The offence involves more than one victim.

Aggravating circumstances pertaining to the act of trafficking

  • The offender used cruelty or brutality demonstrated through deliberate, repeated or gratuitous violence or other forms of degradation;
  • There were multiple victims and/or incidents of trafficking;
  • The offence is committed across borders;
  • Weapons, drugs or medication are used in the commission of the offence;
  • The offence is committed by giving or receiving money or other benefits in order to obtain the agreement of a person who has control over another person;
  • A child has been adopted for the purpose of human trafficking.
Source: UNODC, 2009, pp. 3-11.
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