While the legal definition of stalking varies across jurisdictions, behaviorally, it is generally considered to comprise any of a wide range of repeated acts that either threaten the victim, are intended to cause fear or harm, cause distress, or are otherwise unwanted by the victim. Before the proscription of stalking into criminal law, instances of stalking were sometimes addressed by other criminal laws (such as threats) or by the mental health system. Most of the initial research into stalking was conducted with stalkers who had come into contact with the mental health system. As stalking was criminalized, research extended to include the experiences and feelings of stalking victims as well as the examination of a broader range of stalkers. Additional research has included the manner in which the community perceives stalking behaviors, the factors influencing the occurrence of stalking and stalking violence, and effective strategies for treating stalkers.

Stalking as a Criminal Act

Although stalking may appear to be a new phenomenon, stalking behaviors have existed in some form for hundreds of years. It is only in the last 17 years the behaviors that constitute stalking have been recognized as criminal. Before its criminalization, instances of stalking brought to official attention were often dealt with by mental health professionals. In 1990, the first stalking legislation was instituted in California. A number of cases in which celebrities were stalked, and in some cases killed, by obsessed fans are surmised to have provoked the first law in California. However, stalking came to be recognized as occurring in a range of circumstances, including intimate relationships. Subsequently, all other American states introduced stalking laws (or laws proscribing harassment). Stalking laws have also been instituted in other countries such as England and Australia as well as in many Western European countries. Nevertheless, some stalkers are ultimately managed within the mental health system.

The Mental Health System and Stalking

Before stalking was recognized as criminal, the official response to those who committed stalking was to address their behavior within the mental health system. Some of the first studies of stalking examined stalkers who came into contact with this system. Such research has produced a number of different classifications or typologies of stalkers aimed at guiding approaches for treating the stalker. An example of a classification system used to categorize stalkers and their behaviors is that devised by Paul Mullen and colleagues. Stalkers are classified as rejected (the stalker engages in actions against the victim at the end of a relationship), intimacy seeking (the stalker tries to establish a romantic relationship with the victim), socially incompetent suitors (the stalker tries to establish a connection with the victim but their lack of social skills ultimately leads to their rejection), resentful (the stalker feels the victim has wronged them and wants the victim to feel afraid), and predatory (the stalker revels in the power they have over the person and may sexually assault the victim). Use of this system may permit predictions regarding the likely course of stalking and may lead to suggestions for treatment. However, most typologies are yet to be empirically supported across a sufficient number of studies; therefore, there is a need for ongoing research in this area.

Definitions of Stalking

When stalking was criminalized, legal definitions of the behaviors that constituted stalking had to be devised. Previously, legal remedies could be used only when the stalker had escalated to violence against the victim, which left many stalking victims without legal recourse. The behaviors and requirements encompassed in legal definitions of stalking vary across jurisdictions. The key elements of the California stalking legislation are that stalking behaviors are engaged in, that a threat is made to the victim, and that the stalker intends to pursue the victim. Other stalking laws only possess one or some of these elements. One common element to definitions of stalking though is that stalking is a course of conduct engaged in over a period of time. This course of conduct is one that is unwanted by the victim. Definitions vary in how often stalking behaviors must be engaged in and which behaviors must be displayed. Also, there are differences in whether the stalker needs to have intended to cause some type of harm to the victim and whether a reasonable person would experience fear or some other type of harm.

Clinical definitions of stalking (or obsessional harassment, as is it also known in this field) tend to focus on the repeated nature of the stalking behavior and the fact that it is unwanted and causes distress to the victim. The element of intent to cause fear or harm is generally absent in such definitions. Therefore, there is dissimilarity between some legal and clinical definitions of stalking. This has led to the development of various methods to reduce the problematic behaviors displayed by stalkers. The disparity has also led to research interest in areas such as profiles of stalkers and victims, community perceptions, risk factors, and effectiveness of treatment approaches.


The demographic profile of a stalker is very different from the typical offender profile. Stalkers are generally much older than the typical offender and score higher on intelligence measures than the average offender. Stalkers are usually known to the victim, with a large percentage being current or former partners of the victim. This is in contrast to the often popular perception that victims of stalking are more likely to be pursued by strangers. Stalkers are also overwhelmingly male, which was demonstrated in a survey by Patricia Tjaden and colleagues of 16,000 respondents in the United States, with around 5% of these respondents having been stalked. They reported that approximately 90% of victims in the sample had been stalked by a male.

Victims of Stalking

While men are more likely to be the perpetrators of stalking, women are more likely to be the victims. In the survey by Patricia Tjaden and colleagues, it was found that approximately 80% of the victims were female. This survey also noted that approximately 8% of women had at some stage been stalked, with 2% of men having being stalked during their lifetime. A significant proportion of stalking victims are young adults, with the majority under 30 years.

Other studies conducted with stalking victims have investigated the impact of stalking. These consequences have included psychiatric symptoms, as victims have been known to develop a number of different disorders, such as depression and anxiety, after being stalked. There may also be an impact on victims’ social lives, as stalking victims may be less likely to leave home as they are fearful for their safety. Another impact of stalking may be economic, as the victim may have to take time off work to attend medical or psychiatric services or to attend court hearings. Because of injuries suffered during the stalking period, their functioning at work may also be impaired.

Community Perceptions of Stalking

In addition to research with victims, studies have been conducted into how the community perceives stalking. If the community perceives stalking in a manner different from the conception embodied in the legislation, then police resources may be misused, with stalking incidents reported that do not fit legislative requirements. Such a disparity might also lead to genuine victims not having recourse to legal action as they are not considered stalking victims according to legislation. Thus, research into community perceptions of stalking may prove useful for examining the potential effectiveness of legislation and for suggesting changes to stalking laws.

Some vignette research into community perceptions has found that strangers are more likely to be perceived as stalkers, whereas other research has discovered that ex-partners are more likely to be identified as stalkers. Research has demonstrated that community members are more likely to perceive a situation as stalking when the stalker intends to harm or invoke fear in the victim. Also, when stalkers relentlessly engage in behaviors against their victims, the situation is more likely to be construed as stalking. Unless a low level of repetitive behavior is engaged in, intent to harm the victim is not an important requirement for behaviors to be classified as stalking. Some research has also identified that women are more likely to label certain behaviors as stalking and be more frightened than men who judge the same behaviors. The research reveals that men and women may seek legal assistance under different circumstances.

Risk Factors for Stalking

In addition to research on the characteristics of stalkers and stalking victims, another important area of research has been the examination of factors that increase the likelihood that a person will engage in stalking. Stalking is more likely to occur if there has been a previous intimate relationship between the victim and the stalker. Certain psychological and social traits of the stalker can also increase the likelihood that the person will stalk, such as having a personality disorder or possessing few social contacts. Such contacts can have an impact on the cessation of stalking as these social contacts can convey disapproval of the stalker’s actions to the stalker, which may influence his future decisions to stalk. It is impor-tant for researchers to continue to investigate the factors that influence stalkers to persist in pursuing their victims, as these influencing factors might be altered to reduce the prevalence of stalking.

Violence as an Outcome of Stalking

In some cases, stalkers may escalate to violence against their victims. This violence can have a great impact on the victim and can lead to permanent damage or even death. Some research indicates that stalkers who escalate to violent acts have previous criminal convictions, whereas other research has revealed that having a previous criminal history has no relationship with engaging in stalking behaviors. There are some risk factors, however, that appear to consistently indicate that violence may be a likely outcome. Threats appear to be a precursor to violence in some cases. Some mental illnesses may also lend a person to engaging in violent stalking behaviors, although a psychotic stalker is less likely to engage in violence than a nonpsychotic stalker. The prior relationship between the stalker and the victim can also have an impact on the risk of stalking violence. The presence of a previous intimate relationship is more likely to lead to violence being committed against the victim compared with when the victim is a stranger to the stalker. If the victim’s partner had engaged in substance abuse, this could also likely lead to violence. There needs to be more research conducted in this area to determine what risk factors are the most predictive of a stalker becoming violent.

Treatment of Stalkers

Further research is also required to determine the effectiveness of different methods of mental health treatment for stalkers. It must be noted that there is no treatment regime specifically for stalking, as stalking can be related to a number of mental disorders but itself is not a disorder. Furthermore, not all stalking is related to mental health problems. Thus, it may be difficult to determine the most effective type of treatment or management for stalkers. Despite these issues, some treatment methods have been found to be effective, such as attempting to rectify the disorder underlying the stalking behaviors or concentrating on the behaviors themselves. The victim may also undertake actions, such as legal measures, to attempt to arrest the stalking behaviors.


  1. Dennison, S. M., & Thomson, D. M. (2005). Criticisms and plaudits for stalking laws? What psycholegal research tells us about proscribing stalking. Psychology, Public Policy and Law, 11(3), 384—106.
  2. Rosenfeld, B. (2004). Violence risk factors in stalking and obsessional harassment: A review and preliminary metaanalysis. Criminal Justice and Behavior, 31(1), 9-36.
  3. Spitzberg, B. H., & Cupach, W. R. (2007). The state of the art of stalking: Taking stock of the emerging literature. Aggression and Violent Behavior, 12(1), 64-86.
  4. Tjaden, P., & Thoennes, N. (1998). Stalking in America: Findings from the National Violence Against Women Survey. Washington, DC: National Institute of Justice, Centers for Disease Control and Prevention.

Return to the overview of Victimization in Forensic Psychology.