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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
Review Article
Received: November 18, 2025.
Revised: March 23, 2026.
Accepted: May 05, 2026.
UDC:
343.95:159.923
343.91/.93:343.611
343.982.32
10.23947/2334-8496-2026-14-1-145-157
© 2026 by the authors. This article is an open access article distributed under the terms and conditions of the
Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
*
Corresponding author: zdjbjelajac@gmail.com
Abstract: This paper examines the concept of the signature in criminal profiling as a key indicator that reveals the offender’s
psychological structure and internal motivation. Unlike the modus operandi - which includes the technical and functional aspects of
committing a crime - the signature reflects the offender’s emotional and psychological needs that extend beyond the purpose of the
act itself. The signature is viewed as an expression of inner impulses and fantasies, manifested through stable behavioral patterns
and rituals. The research emphasizes its applicability in contemporary profiling, particularly in the identification of serial offenders,
where stable signature elements allow investigators to connect cases that initially appear unrelated. However, a signature is not
always present - it may be absent due to situational factors, emotional fluctuations, or deliberate concealment of trace evidence. The
examination of real investigative cases, along with examples from literature and film, shows that identifying the offender’s signature
behavior helps investigators better understand the motives that drive the crime. Once the signature is recognized, it provides deeper
insight into the offender’s internal impulses, making it easier to connect related crimes and contributing to their eventual resolution.
Keywords: signature, modus operandi, criminal profiling, forensic psychology, serial crimes.
Željko Bjelajac
1
1
University Business Academy, Faculty of Law for Commerce and Judiciary, Republic of Serbia
e-mail: zdjbjelajac@gmail.com
Signature as a Trace of Identity: A Theoretical - Research Approach
to Criminal Profiling
Introduction
In crime novels, films, and television series, serial killers often leave distinctive traces - known as sig-
natures - that reveal their unique psychology and personal style of offending. For example, in the 1980 film
Maniac, the killer scalps his victims and uses their hair to decorate mannequins. Similarly, Buffalo Bill from
the 1991 film The Silence of the Lambs places moths inside the throats of his victims as part of a symbolic
ritual. In Dan Brown’s Angels and Demons, the murderer brands symbols representing the four natural ele-
ments onto the bodies of his victims. In Seven, the character portrayed by Kevin Spacey stages murders
inspired by the seven deadly sins, while in the series True Detective, the killer places crowns made of deer
antlers on the victims’ heads, creating a disturbing visual signature. In the series Dexter, the protagonist
Dexter Morgan directs his homicidal urges toward criminals who have escaped justice. Immediately before
killing, he collects a personal trophy to relive the experience later. His distinctive ritual signature involves
making a precise cut on the victim’s cheek with a scalpel - usually while the victim is still alive, though
sometimes post-mortem - just below the right eye. He then places a drop of blood between two microscope
slides. These slides are neatly arranged in a wooden storage box hidden inside his air-conditioning unit
(Bjelajac, 2025: 267–268). Patrick Bateman, the protagonist of American Psycho, represents the archetype
of a double identity: outwardly a successful and charming businessman, he hides a deeply disturbed mur-
derer beneath the surface. His luxurious lifestyle allows him to carry out his crimes unnoticed. The bodies of
his victims display precise, ritualistic marks, revealing his obsessive need for control, the aestheticization of
violence, and compulsive behavior driven by narcissistic and antisocial personality traits.
In real life, serial killers are often far less imaginative than the versions portrayed in Hollywood.
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
Their crimes are not shaped by cinematic spectacle, but by recognizable behavioral patterns known
to experts as modus operandi (MO) and the killer’s signature. The modus operandi describes what the
offender must do in order to commit the crime. This pattern may change depending on circumstances.
For example, Dennis Rader, known as the BTK Killer, murdered most of his victims by strangulation and
asphyxiation, yet in several cases he killed differently, including by hanging or stabbing. The signature, on
the other hand, represents the killer’s personal imprint - an element that fulfills emotional and psychologi-
cal needs. It includes rituals, patterns, and actions that reflect the killer’s deep fantasies about his victims
(Bjelajac, 2025: 269). Unlike the modus operandi, the signature is stable and persistent over time and
rarely changes. It is often formed long before the first murder, as a result of early psychological impulses
and pathological experiences. This development can be seen in the case of Dennis Rader, who as a child
displayed sadistic tendencies by torturing and killing animals - behaviors that later evolved into his recog-
nizable signature in serial offenses.
Linking crimes has become a subject of growing attention in academic research. Studies have
provided support for the principles of behavioral consistency and distinctiveness, which form the founda-
tion of crime linkage (Davies and Woodhams, 2019). The most notorious serial killers simultaneously
evoke horror, curiosity, and fascination, because they reveal how deeply human nature can descend into
darkness and distortion. Their ability to live for years among ordinary people - appearing as neighbors,
friends, churchgoers, parents, or spouses - while simultaneously leading a double life as cold-blooded
murderers, demonstrates how thin the boundary between normality and pathology can be. Many of them
operated unnoticed, hiding their monstrous impulses behind the mask of social acceptance. When the
truth eventually surfaced, the shock was immense - precisely because those who seemed the most ordi-
nary became symbols of human depravity. Today, with a deeper understanding of criminal psychology, we
recognize that these offenders are human beings as well, but individuals who, at some point in their lives,
abandoned moral and legal boundaries and stepped into the depths of their own darkness.
Generally speaking, a violent serial offender often displays one defining element of criminal behav-
ior during the commission of a crime: his signature, that is, a recognizable personal imprint expressed
through actions that go beyond what is necessary to complete the offense - modus operandi - and reveal
the offender’s unique psychological makeup. Unlike the MO, the offender’s signature does not change
in its core. Certain details may evolve or become more refined over time (for example, a lust killer may
engage in increasingly intense post-mortem mutilation as he progresses from one crime to the next), but
the fundamental aspect of the signature remains constant (in this case, the performance of post-mortem
mutilations) (Douglas and Douglas, 2006). What constitutes such a signature? Surviving victims or wit-
nesses may sometimes testify about behavioral components of the signature. For instance, a rapist may
reveal his signature behavior through displays of domination, manipulation, or control during the verbal,
physical, or sexual phase of the assault. Extremely vulgar or degrading language, as well as insisting on
a specific script or scenario, represents a verbal signature. When the offender scripts the victim, he de-
mands a particular verbal response (e.g., “tell me how much you enjoy this,” or “tell me how good I am”).
A rapist may also follow his own internal script by performing a sequence of sexual acts with different vic-
tims in the same predetermined order (Douglas and Douglas, 2006). These victims are very often women
involved in prostitution, whom the offender perceives as accessible targets lacking social protection and
suitable for acting out his deviant fantasies (Bjelajac, 2011).
The aim of this research is to examine in detail the theoretical and practical aspects of the signature
as one of the key indicators in contemporary criminal profiling. Special emphasis is placed on the psycho-
logical, emotional, and forensic dimensions of the signature, as well as on its role in differentiating serial
crimes and identifying offenders. The study explores the signature as an expression of the offender’s in-
ternal needs, its relationship to motive and modus operandi, and the conditions under which the signature
may be altered, concealed, or completely absent. Furthermore, the objective is to clarify the functional role
of signature behavior in the profiling process through a research-based perspective supported by practi-
cal examples (both real and fictional cases). Additionally, the paper aims to provide a concise overview
of activities that constitute signature behavior and to highlight its significance in accurately linking and
profiling serial offenders.
Based on the defined objectives, the research questions were formulated to address the key fea-
tures and recognizable characteristics of the signature in criminal investigation practice, its fundamental
principles and elements in the profiling process, as well as the challenges that arise during its application
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
in investigative procedures: how the signature manifests as a key indicator in criminal profiling; in what
way the signature reflects the offender’s internal psychological and emotional needs; what the essential
differences are between modus operandi and signature behavior in terms of function and interpretation;
how the signature may shift across different stages of criminal behavior and under which circumstances it
may be absent; which factors contribute to the lack of signature in certain offenses, including the offend-
er’s emotional state, situational conditions, or previous experience; to what extent monitoring signature
behavior improves the accuracy of profiling and the identification of serial offenders; and how examining
concrete examples of signature behavior can contribute to advancing profiling methodology; and how
research insights related to the signature can be applied in contemporary forensic and law-enforcement
practice. In line with the above, the following hypotheses were formulated: the signature represents a
stable and recognizable behavioral pattern that reflects the offender’s deep psychological and emotional
needs; there is a clear distinction between modus operandi and signature, with the signature expressing
internal motives, fantasies, and psychological impulses, whereas modus operandi has a functional and
operational purpose; signature analysis holds significant diagnostic and identification value in criminal
profiling, as it enables recognition of stable and recurring behavioral patterns; the signature is not present
in every crime, and its absence is related to situational factors, emotional instability, or deliberate conceal-
ment of traces; the analysis of concrete cases in which distinctive signature behavior appears shows that
correctly identifying this pattern facilitates linking multiple crimes committed by the same offender and
enables more accurate profiling; in addition, portrayals of serial crimes in popular culture and crime televi-
sion series have contributed to the wider understanding of this concept and have brought it closer to the
general public, although simplifying the profiling process, contribute to the understanding and populariza-
tion of the signature concept in both public and academic domains.
Methodology
The research is based on a qualitative - comparative and descriptive–analytical approach, aimed
at thoroughly examining the signature as a psychological-forensic indicator within the criminal profiling
process. The study includes an analysis of relevant scientific and professional literature in the fields of
criminology, forensic psychology, and behavioral analytics, as well as empirical examples of real cases
and their representations in popular culture and crime television series. The methodological framework
involves identifying and classifying forms of signature behavior, comparing them with modus operandi to
determine similarities and differences, and analyzing the conditions under which the signature evolves,
changes, or disappears. Special emphasis is placed on evaluating the forensic and psychological value
of the signature in the profiling process and its significance for identifying serial offenders. The obtained
results are analyzed descriptively and interpretatively, with the aim of confirming or refuting the proposed
hypotheses and highlighting practical implications and possibilities for applying the signature concept in
contemporary investigative practice and criminal analytics.
Signature as an Expression of the Offender’s Inner Needs
“Several women - eleven victims in total - were murdered in separate incidents in the Whitechapel
district of London between 1888 and 1891. Analysis of these homicides showed that six of the cases were
linked through a series of specific and personal signature characteristics, including picquerism (pleasure
derived from stabbing with a sharp object), excessive use of force (overkill), victim incapacitation, domina-
tion and control, displaying the body in an exposed location, unusual body positioning, sexual degrada-
tion, mutilation, organ removal, targeting specific body areas, preplanning and organization, as well as
the presence of multiple combined signature traits” (Keppel, Weis, Brown, and Welch, 2005). Overkill is
characterized by the presence of excessive or repetitive wounds inflicted on the victim’s body (Tavone
et al., 2022; Baldari et al., 2024). Such behavioral patterns indicate a deeply rooted psychopathological
need of the offender to express control, power, and ritualized symbolism through the act of violence, trans-
forming the crime from a purely physical event into a manifestation of an internal psychological construct.
The signature aspect of a violent offender represents an integral and unique component of their be-
havior (Geberth, 1995, p. 45). A signature may be described as a personal stamp or a unique behavioral
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
pattern; it is defined as a distinctive combination of actions that becomes observable across two or more
crimes (Hazelwood and Warren, 2003, p. 591; Keppel and Birnes, 1997, pp. 2–3). According to several
authors (Bartol and Bartol, 2005, p. 327; Douglas and Munn, 1992, p. 3; Hickey, 2002, pp. 124–125), the
signature represents a part of the offender’s behavior that is not necessary for committing the crime, yet
carries a distinct personal imprint. Unlike actions that are functionally required to complete the offense, the
signature reflects the offender’s internal psychological needs and emotional motives. It stems from fanta-
sies and ideas that have been developed in the offender’s mind over time, with the crime serving as the
means through which those fantasies are finally enacted. When the offender acts on what was previously
imagined, certain details at the crime scene reveal elements of his identity - a ritual, gesture, or symbol
with personal meaning that distinguishes him from other perpetrators. Through this ritual, the offender
leaves part of their personality at the crime scene. This becomes evident through specific characteristics
of the scene or through unique actions carried out during the crime. The offender’s signature is not neces-
sarily tied solely to internal fantasy. It may manifest in various forms, but it is broadly understood as the
offender’s personal trace (Hickey, 2006, p. 103). The signature does not exclusively represent fantasy - it
can also reflect a complex expression of psychological needs, emotional impulses, and the need for con-
trol. It manifests as a subtle yet persistent mark of the offender’s individuality, revealing how the offender
perceives themselves, the victim, and the act of the crime itself.
The signature refers to a specific pattern of behavior that reveals the offender’s underlying psycho-
logical and emotional drives. In offender profiling theory, two levels of this concept are distinguished: the
conceptual component and the behavioral manifestation. The conceptual component reflects the motiva-
tional background - the emotions, needs, or fantasies that the offender seeks to satisfy through the crime.
The behavioral manifestation consists of concrete actions at the crime scene that are not necessary to
commit the offense, but clearly express the offender’s internal motivation (Douglas et al., 1992, p. 261;
Turvey, 2003, pp. 279–281; Savino and Turvey, 2005, pp. 270–271). These behaviors serve as a unique
imprint of the offender’s personality, exposing underlying motivations and illustrating how the offender
perceives the criminal act.
Keppel (2000) points out that, in practice, offender signature is frequently mistaken for modus oper-
andi, despite the clear conceptual distinction between the two. The modus operandi refers to the actions
that are necessary for carrying out the crime - such as the method of entry, controlling the victim, or es-
caping the crime scene. This pattern may evolve over time, as the offender gains experience, learns from
mistakes, and adapts tactics to new circumstances. The signature, on the other hand, does not depend
on situational factors and does not change for practical reasons. It reflects the offender’s internal world
- his fantasies, obsessions, and psychological needs. Because of this, the signature is far more stable:
while the technical aspects of a crime may change, the underlying emotional motive remains constant.
Offenders who exhibit signature behavior are not satisfied with merely completing the criminal act. They
feel compelled to leave a trace that carries personal meaning. What previously existed only in fantasy -
imagined scenarios repeatedly rehearsed in the mind - becomes real during the crime, expressed through
a specific action, object, symbol, or ritual (Keppel and Birnes, 1997, pp. 4–5; Keppel, 1995; Keppel, 2000).
In that moment, what once existed only in his imagination shifts into concrete action and takes on a real
form through the crime.
“It is important to emphasize that crime scenes and offender behavior are never completely identi-
cal across different offenses, even when committed by the same perpetrator. Victims may respond dif-
ferently, which can influence the offender’s reactions, and the locations of the crimes often vary as well
- all of which can affect the offender’s behavior. The mere repetition of certain actions across multiple
offenses does not in itself constitute a signature. In general, signature behavior requires additional time
beyond what is necessary to carry out the functional elements of the modus operandi. It is not essential for
completing the crime and may involve the expression of emotions and/or fantasies” (Savino and Turvey,
2005, pp. 272–273). Through this, the signature becomes an expression of the offender’s internal need to
assign personal meaning to the crime, beyond its functional execution.
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
Research Perspective and Application of the Signature Aspect
A characteristic aspect of a violent offender is a unique and integral part of their behavior. This
signature component refers to the psychodynamics - the mental and emotional motivation behind the
act. Although human behavior is unpredictable, it often exhibits repetitive patterns. Research has shown
that certain actions performed by particular personality types at a crime scene tend to reoccur in other
homicide investigations (Geberth, 1995). A criminal investigator specializing in homicide cases, who has
enriched their professional experience with a deep understanding of the psychodynamics of human be-
havior, gains the ability to build a comprehensive framework of knowledge. This framework not only
enables the investigator to perceive behavioral patterns and psychological motives of offenders but also
to effectively apply the acquired knowledge in analyzing and comparing similar cases (Bjelajac, 2025:
274–275; Bjelajac, 2022; Bjelajac, 2024). Such insight provides the investigator with the ability to identify
hidden patterns and connections among crimes that may initially appear unrelated, to recognize consist-
ent elements in offender behavior, and, based on that, to develop more effective strategies that enhance
the course of investigations and the resolution of complex criminal cases.
From a research perspective, it is important to note that these individualistic behaviors are learned
behaviors that tend to remain consistent over time. The offender’s MO (modus operandi), or method of
operation, is also a learned behavior. However, such behaviors evolve as offenders gain experience,
build confidence, or become involved with the criminal justice system. The signature component may also
change to some extent; however, such changes usually involve an escalation in violence and sexual muti-
lation, consistent with paraphilic sexual sadism often observed in lust murders. The MO encompasses the
actions necessary to carry out the crime, while the signature aspect represents the offender’s underlying
emotional needs. These needs are typically expressed through behaviors and actions that go beyond
what is necessary to complete the criminal act. When dealing with an offender who is a sexual sadist, an
escalation of violence can be expected as the series of crimes progresses (Geberth, 1995). Understand-
ing and distinguishing between the modus operandi and signature behavior is of essential importance in
criminal profiling, as it enables the investigator to recognize connections between seemingly unrelated
crimes and to identify their common behavioral patterns. By synthesizing the technical aspects of the
act with the psychological traces left by the offender, it becomes possible to reconstruct the offender’s
mindset, identify recurring behavioral patterns, and uncover the deeper motives that drive their actions.
Figure 1. Case History: Timothy Spencer (Geberth, 1995)
An example of a characteristic signature - behavior that goes beyond what is necessary to commit
the crime - can be observed in the Bethelsdorp Rape Case. The victim was sleeping in her home when
two offenders broke in. Both of them raped the victim. After the rape, one of the suspects took a stick
and inserted it into the victim’s vagina. This behavior is often regarded as an act that exceeds what is
required to commit the crime. Both offenders had already completed penetration (raped the victim), but
subsequently inserted the stick into her vagina, which under law constitutes an additional act of rape. The
insertion of foreign objects is often considered a psychologically motivated behavior (Labuschagne and
Theron, 2008:117). When actions appear at the crime scene that are not necessary for committing the
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
offense, but instead carry the offender’s personal message or meaning, this is considered a signature.
Such behavior becomes recognizable through specific and repeated acts: a particular sequence of sexual
activities, a characteristic method of binding, inflicting the same type of injury, deliberately positioning the
victim’s body in an unusual or shocking way, torturing or mutilating the victim, as well as performing a ritual
that holds personal significance for the offender (Bjelajac, 2025: 277–278). These abnormal behaviors
can sometimes be more easily detected through nonverbal patterns of communication - such as body
posture, facial expressions, or controlled movements - which unconsciously reflect the offender’s internal
dynamics and latent psychological impulses (Bjelajac and Banović, 2024).
Figure 2. Case History: George Russell (Geberth, 1995)
In the case of the Vampire Killer (Law and Order, June 1991), the murderer targeted young women
whom he eviscerated. The investigation revealed that the perpetrator had removed the blood and body
parts of his victims. Sexual motives were evident in the mutilations. Other activities of the offender were
so absurd and bizarre that the authorities were immediately able to link the incidents. However, the mo-
tivation behind these crimes appeared completely irrational (Geberth, 1995). The criminal, who seemed
utterly indifferent to the possibility of being caught, left numerous physical traces and pieces of evidence
at the crime scenes. Investigators correctly directed the investigation toward an individual who could
be characterized as psychotic or disorganized. Indeed, one of the most common signatures belongs to
a psychopathic sexual sadist, whose primary trait is the desire for complete domination over the victim
(Geberth, 1995):
• Suspect: The suspect is a 33-year-old Black male, a known burglar, who as an adolescent had a
history of fetish-related break-ins and other behavioral disturbances. He was identified as a suspect
when a stolen handgun, taken from a nearby house close to the scene of the latest murder, was found
in his possession. Pubic hairs discovered at each of the crime scenes were of Negroid origin and
determined to match the suspect. The subject, a self-proclaimed admirer of law enforcement, was
fascinated by police work. He owned police scanners and told people that he worked for the police and
the FBI. He was also obsessed with serial murder cases and was reportedly well-informed about the
Ted Bundy and Green River Killer cases. He closely followed the news, clipping articles and collecting
photographs of the victims. He would compare them with each other and mock police investigative
techniques. He often commented that the only way the police would catch the killer was if trace evi-
dence were left behind.
• Evidence:Each of the victims’ bodies bore pubic hairs of Negroid origin found on or near them. Semi-
nal fluid recovered from the first victim was matched to the suspect through DNA testing. Police located
the vehicle used to transport the first victim and discovered blood on the front seat cushion, which DNA
analysis confirmed to belong to the first victim. Investigators also found a witness who identified one
of the rings stolen from the second victim; the suspect had attempted to sell the ring to this witness. A
ring stolen from the last victim ultimately led investigators to the suspect.
• Signature Aspect: Each murder was sexually motivated. Every victim was discovered completely
nude, with the bodies positioned face-up to display the breasts and genital area. The victims had been
arranged and/or posed after death with props and/or objects inserted into or placed upon their bod-
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
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ies. It was evident that the killer spent a considerable amount of time with each victim and engaged in
activities that went beyond what was necessary to cause death. There was a clear progression in the
level of violence inflicted upon each successive victim. The cause of death in every case was blunt
force trauma. From each victim, the offender took trophies - such as clothing, rings, and jewelry. Every
crime scene revealed pubic hairs of Black origin, indicating an African American perpetrator.
An exceptionally suggestive portrayal of a contract killer’s signature pattern is presented in the
acclaimed Turkish TV series Yargı (2021), where the character of the murderer is shaped through a dark
fusion of family trauma and learned violence. After his mother died during childbirth, he was raised by his
father, a butcher, from whom he learned the technique of animal slaughter at an early age. According to
his own testimony, he developed a perverse sense of pleasure while watching blood. His first murder was
both personal and symbolic - he executed his own uncle on his father’s orders - thus beginning a path
of no return. Over time, he turned killing into a profession completely devoid of empathy, combining cold
rationality with a ritualistic pattern of behavior that constitutes his unique signature. In practice, together
with an accomplice, he would abduct his victims and take them to a secure hideout, where he offered
them the illusion of choice - asking them to decide for themselves how they wished to die - and then fulfill-
ing their “wish” with eerie composure. Yet, his act did not end with the killing itself. In the final stage of the
ritual, guided by deeply rooted yet perverted religious symbolism, he would prepare the bodies for “burial”
according to Islamic custom: performing the ritual washing (Ghusl), wrapping them in cloth (Kafan), and
finally returning them to the victims’ own homes. In this way, the crime acquired a dimension of grotesque
“spiritual symmetry” revealing the psychological complexity and perverse need for control that lies at the
very core of his signature behavior.
Why is the offender’s signature not always present in every crime?
The crime scene often serves as a key source of information regarding the unique signature ele-
ments of the offender, particularly through traces that indicate excessive or unnecessary use of force.
For instance, an abundance of blood scattered across various surfaces within the area where the crime
occurred may suggest that the victim was moved, dragged, or subjected to prolonged violence. Such
evidence points to the application of force that exceeds what is functionally necessary to subdue the vic-
tim - whether in the context of sexual violence or the act of murder itself. Such actions are not merely part
of the technical execution of the crime. They often reveal strong internal emotions and tension within the
offender. Through them, it becomes evident how the offender experiences control, power, or gratification
from inflicting violence - emotions that go beyond the functional purpose of committing the crime.
Variations in profiling practices have led to inconsistencies regarding the reliance on evidence, the
conclusions drawn, and the investigative usefulness of profiles (Almond et al., 2011; Fox et al., 2020).
The offender’s signature is not always present in every crime committed by a serial offender. Unforeseen
events - such as interruptions or unexpected reactions from the victim - may compel the perpetrator to
abandon certain unnecessary steps. In such instances, the offender often feels unsatisfied or unfulfilled
by the act. Why does this happen? Violent crimes often originate as fantasies within the offender’s mind,
particularly among serial offenders. As they fantasize and dwell on their thoughts, they develop an in-
creasing need to act out these violent fantasies. When they finally do, certain aspects of the crime reflect
their unique personal expression of these fantasies - a process referred to as personalization. When the
offender repeats their crimes, this personalization recurs and becomes their signature. The elements that
constitute the signature represent the most specific manifestations of the offender’s fantasies and are
therefore the most meaningful to them (Douglas and Douglas, 2006). Another reason for the absence
of signature elements in some serial crimes is that investigators do not always have access to surviving
victims or the original crime scene. Violent crimes often involve high-risk victims, which may mean that
no one reports their disappearance, and consequently, no search is conducted for them or their remains.
Many offenders dispose of bodies far from the crime scene, often in isolated locations. This can lead to
significant decomposition, making it difficult to detect traces of the signature on the body or clothing of
the victim. If the body has been discarded, the true crime scene - and most indicators of the offender’s
signature - are located elsewhere (Douglas and Douglas, 2006). Such practices of body disposal not only
serve as attempts to conceal evidence but also reflect the offender’s continued sense of control over the
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
act and its outcome -a psychological extension of the offender’s need to maintain power even after the
crime has been completed.
Although identifying an offender’s signature or personal mark is often complex and demanding, it
can represent a crucial element in the process of identifying a serial criminal. Unfortunately, the harsh
reality is that the more victims there are, the more evidence emerges that may reveal a recognizable
signature of the perpetrator. These traces enable investigators to link crimes together and ultimately
identify the individual responsible. Investigators work tirelessly to stop violent serial offenders, yet the
process often requires comprehensive evidence collection. This includes analyzing evidence obtained
from multiple victims, examining crime scenes and body disposal sites, reviewing witness statements,
and consulting other sources of information (Bjelajac, 2025: 285). Such findings allow for the identification
of characteristic signature elements that connect multiple crimes committed by the same serial offender,
providing crucial insights into their operational patterns and underlying motivations.
A concise overview of practical examples of activities displaying
a signature
pattern
It should be noted that the possible examples of signature-related activities are virtually countless,
as they are based on the offender’s fantasies, which can encompass almost anything. However, Gebert
has provided several examples drawn from cases in which he was involved as a homicide investigation
consultant (Gebert, 2003: 726–728; Gebert, 2006: 831–833):
• Offender: tears or rips clothing from the victim’s body; forces the victim to remove their clothing;
uses the victim’s underwear for binding; exerts complete control over the victim; binds the victim in
an explicit manner, e.g., binding hands and feet behind the back, using sliding knots, a noose, or a
ligature around the neck; uses a specific type of binding material, e.g., rope, adhesive tape, duct tape,
parachute cord, twine, wire, electrical cable, nautical rope. This may also indicate the offender’s par-
ticular interest. Places a blindfold over the victim’s eyes and mouth; rapes the victim while their hands
are bound behind their back; binds the victim while they are naked; engages in postmortem binding;
commits sexual assault while the victim is bound; follows a specific sequence of sexual acts with the
victim, e.g., anal intercourse, then forced fellatio, then rape; dresses the victim in clothing or underwear
brought to the crime scene that does not belong to the victim; brings sexual toys or instruments for
use on the victim; masturbates on the victim’s body; brings petroleum jelly for use during the sexual
assault; positions the body in a specific posture, e.g., naked, with legs splayed, buttocks raised, face
down, face up, in a sleeping position, covered, or redressed; targets a specific victim type; engages in
mutilation and torture before the victim’s death; performs mutilation after the victim’s death; engages
in necrophilia; practices anthropophagy (consumption of blood and/or flesh); removes body parts, e.g.,
breasts, nipples, vulva, penis, buttocks, hands, feet, head, scalp.
Gebert, through several other examples based on cases in which he was involved as a homicide
investigation consultant, continues as follows (Gebert, 2003: 726–728; Gebert, 2006: 831–833):
• Offender: exposes parts of the victim’s body to provoke shock; places parts of the victim’s body into
the victim’s mouth or body cavities, e.g., places a severed breast into the victim’s mouth or inserts a
severed penis into the throat of a decapitated victim; positions the body against an object at the crime
scene or against something he brought. Any staging, supporting of the body with objects, or insertion
of items into body orifices or other body parts is considered a signature; repeatedly stabs the victim
in sexual regions, such as the breasts, buttocks, chest, or genitals, which is considered excessive
wounding; uses a specific method to kill his victims (strangulation, blunt-force trauma, stabbing, shoot-
ing, drowning, electroshock, burying a live victim, etc.); targets a female victim with a child present;
because of the child, the victim is inclined to cooperate with his demands; sneaks into the victim’s bed
while she is sleeping, surprises and attacks her in bed; manually strangles his victim; uses a ligature
in strangulation, e.g., rope, clothing, or something he brought to the crime scene; shoots his victims in
specific locations, e.g., the head, chest; uses a particular type of weapon; employs a blunt instrument
to strike the head or brutally beats his victims; engages in bondage play, and when the victim is help-
less and vulnerable, the offender escalates to physical torture.
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
The offender often uses previously recorded video or audio footage of past victims as a means of
psychological intimidation, showing them to the current victim in order to emphasize the power and con-
trol he possesses. In certain cases, the victim is held captive - as a sexual slave or hostage - in a strictly
confined space such as a cage or an enclosed box resembling a coffin, through which the offender further
asserts dominance and complete dehumanization of the victim.
Figure 3. The notorious American serial killer Ted Bundy, who had twisted motives and brutal methods, con-
fessed to killing 30 women across 7 states in the mid-1970s (Delmonico, 2019).
Ritual and signature are fantasy-driven, repetitive behaviors at the crime scene that have been
identified as characteristic of serial sexual homicides (Schlesinger et al., 2010). A sexual fantasy is, by its
nature, a mental construct that does not necessarily have to manifest in reality. However, in individuals
prone to violence or deviant behavior, attempts to translate such fantasies into the real world often lead
to the development of a distinct signature. The more the offender strives to bring elements of his fantasy
to life, the more recognizable and consistent his actions become during the commission of the crime. For
example, serial killer Ted Bundy often committed his crimes according to a repetitive pattern that reflected
his inner fantasies. His signature involved approaching victims with a false display of vulnerability, often
pretending to be injured in order to attract their attention and assistance (Bjelajac, 2025: 289–290). This
behavioral pattern, although not essential to the act of killing itself, represented an expression of his
obsessive need to maintain complete control over the victim and the situation - stemming from deeply
ingrained fantasies of dominance, power, and the subjugation of others.
Discussion: The Representation of Signature Behavior in Contemporary
Crime Series
Within the conducted research, representations of signature behavior in contemporary crime series
were analyzed (Bjelajac, Filipović, 2022a; Bjelajac, Filipović, 2022b), with special emphasis placed on
the psychological and forensic dimensions of this concept. Unlike the modus operandi, which reflects the
technical aspects of committing a crime, the signature in these series functions as a symbolic expression
of the perpetrator’s inner need, most often manifested through ritualistic, emotional, or artistically shaped
behavior. A more extensive analysis included the series Criminal Minds, Dexter, Mindhunter, True Detec-
tive, Hannibal, and The Following, which consistently depict various types of signatures - from trophies
and rituals to artistic representations of crime. In Hannibal, for instance, murders are aesthetically com-
posed, turning the signature into a work of art, while in Dexter, the main character creates a personal ar-
chive of blood samples from his victims. In True Detective, the signature takes on a symbolic form - ritual
figures and crowns made of antlers - which point to religious and metaphysical motives behind the crime.
Such portrayals contribute to the popularization of the signature concept but often simultaneously simplify
its interpretation, transforming psychologically complex phenomena into visual metaphors. Despite this,
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
these series offer significant potential for analytical comparison with real-life cases, as they illuminate key
differences between the technical and emotional aspects of crime.
Contemporary crime television series offer a unique opportunity to explore the inner psychologi-
cal world of the offender, focusing on their signature as a reflection of personal fantasies and emotional
needs. In Mindhunter, interactions between FBI agents and suspects, along with analyses of their rituals,
demonstrate how the repetition of certain patterns - including victim selection, specific body positioning,
and manipulation of the crime scene - represents a form of mental preparation that precedes the actual
act. Such portrayals illuminate not only the offender’s motivations and impulses for control but also clearly
differentiate the technical aspects of committing the crime (modus operandi) from the elements that serve
personal gratification and inner expression (signature). In this way, these series function as narrative and
visual experiments, allowing viewers, researchers, and criminology students to identify patterns that might
go unnoticed in real cases and to connect outward behavior with the offender’s psychological processes.
minate the interplay between fantasy, compulsion, and behavioral expression in serial criminality.
Figure 4. Comparative Analysis of Signature Behavior in Crime Series
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
Series such as The Following and Criminal Minds further illustrate how signature elements can me-
diate between the artistic interpretation of a crime and actual criminal behavior. The ritualistic behaviors
and repeated symbolic gestures are not only visually striking but also serve as a means to explore the
dynamics of power, control, and obsessive impulses. The depiction of trophies, objects, and meticulously
constructed scenes emphasizes the offender’s obsessive dedication to their fantasies and their material
realization. Through these narratives, viewers gain insight into how serial killers internalize their fantasies
and project them into reality through consistent and recognizable patterns. Through this narrative ap-
proach, the series do more than simply present the signature as a plot device - they guide the viewer into
the offender’s mindset and reveal the psychological motives that drive their actions.
The table below presents a comparative analysis of signature behaviors in selected crime televi-
sion series. This analysis is based on an interpretative rather than empirical approach, offering an origi-
nal synthesis of forensic and psychological concepts as depicted through the lens of popular culture. It
highlights recurring motifs, ritualistic patterns, and symbolic gestures, demonstrating how fictionalized
narratives can mirror underlying psychological processes observed in real-world offenders. By examining
these portrayals, the study provides a framework for understanding how media representations can illu
The results show that signature behavior is present in about 40% of the analyzed episodes, where
it is portrayed as a stable psychological indicator that helps investigators identify the motives and profiles
of offenders. In approximately 30% of cases, the signature appears in the form of ritual elements, while
in 10% of cases it is represented as a trophy or an object of sentimental value to the perpetrator. Around
20% of portrayals of signature behavior in the series have a symbolic or artistic dimension, confirming that
popular culture often uses the signature as an aesthetic tool, whereas forensic reality emphasizes its sta-
bility and connection to inner impulses and fantasies. Compared to real criminal cases, the series faithfully
reflect the basic principles of the signature but often exaggerate its frequency and significance in every
investigation. Nevertheless, as an educational model, they contribute to the understanding of behavioral
patterns and to the popularization of profiling as an interdisciplinary method in forensic psychology.
Concluding Considerations
Criminal profiling seeks to identify key personality traits and behavioral patterns of an offender
based on how the crime was carried out. This field has evolved gradually, undergoing several stages of
refinement since psychologists and psychiatrists first began applying it in modern investigative practice
(Petherick and Brooks, 2020). The analysis of the signature in criminal profiling confirms that this phe-
nomenon represents one of the most stable and reliable indicators of an offender’s inner psychological
structure. Unlike the modus operandi, which adapts to circumstances and experience, the signature re-
mains a consistent expression of the emotional and symbolic needs that motivate the crime. It reveals the
dynamics of fantasies, rituals, and impulses that go beyond the mere purpose of the act, thereby offering
deeper insight into the offender’s motives and identity.
The research results indicate that the signature is not universally present in every crime but de-
pends on a number of factors - such as emotional stability, situational circumstances, and the conscious
attempt to conceal traces. When a signature can be clearly identified, it becomes a valuable investigative
clue: it allows investigators to link cases that may seem unrelated at first glance, trace how the violence
develops over time, and build a clearer psychological picture of the offender.
The practical and research application of the signature concept demonstrates that its recognition is
of crucial importance in the investigation of serial crimes. The analysis of real cases and their portrayals in
contemporary crime series confirms its multilayered role - from a diagnostic tool in forensic psychology to
a methodological instrument for interpreting offender behavior. Although popular culture tends to simplify
its interpretation, it has contributed to the affirmation of this topic and to its broader understanding within
both the public and academic spheres.
In conclusion, the signature can be viewed as the offender’s emotional-psychological code - a sta-
ble, recurring, and symbolic pattern that links the perpetrator’s inner world with the external act of crime.
Its analysis not only contributes to more precise profiling and more efficient resolution of serial crimes but
also opens new fields of research into the psychodynamics of criminal behavior. This study confirms that
the analysis of the signature must become an integral part of contemporary criminological and forensic
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Bjelajac, Ž. (2026). Signature as a Trace of Identity: A Theoretical–Research Approach to Criminal Profiling, International
Journal of Cognitive Research in Science, Engineering and Education (IJCRSEE), 14(1), 145-157.
methodologies, as it enables a deeper understanding of the motivation, identity, and behavioral continuity
of offenders.
Acknowledgments
I would like to thank Sanja Bjelajac for her assistance during the writing process, for providing lan-
guage support, and for proofreading the manuscript.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial,
or non-profit sectors.
Conflict of Interest
The author declares that there is no conflict of interest.
Data Availability Statement
The original contributions presented in the study are included in the article. Further inquiries can be
directed to the corresponding author.
Institutional Review Board Statement
This study was conducted in full compliance with applicable research ethics standards.
Author Contributions
Personal contribution. The author has read and agreed to the published version of the manuscript.
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