Prosecution of Cases Involving Sexual Crimes without Physical Evidence

Sexual crimes comprise a profound violation of human rights, leaving victims with emotional, physical, and psychological damage that can take a lifetime to recover. These crimes range from harassment and assault to rape and child abuse [1]. Worldwide, such crimes remain alarmingly dominant, as the World Health Organization (WHO) reports that one in three women has experienced some form of physical or sexual abuse in her lifetime [2]. In America, an individual is sexually assaulted every 68 s, and only 2.5% of the offenders end up in prison [1].

Such felonies are prosecuted under criminal law, which holds criminals accountable while ensuring that the rights of both victims and defendants are maintained. To establish culpability beyond a reasonable doubt, the prosecution’s case strategy generally stands on a combination of physical, forensic, and testimonial evidence [3,4]. The challenges turned out to be even more pronounced during the trial. Prosecutors have the responsibility of presenting a case that meets the standard of proof beyond a reasonable doubt. In contrast, the defense often emphasizes discrediting the testimony of the victim or taking advantage of inconsistencies in narratives [5,6].

Forensic evidence holds a crucial role in establishing the facts of a case. Biological evidence, such as blood, hair, saliva, or semen, can corroborate the testimony of the victim, link the accused to the crime scene, and prove physical contact [7,8]. In the majority of cases, victims avoid talking about sexual abuse due to shame or psychological trauma, leading to the degradation and complete loss of forensic material [9]. In underprivileged areas with inadequate healthcare infrastructure, victims may lack access to proper medical and forensic examinations, which leads to the absence of physical evidence [10]. Sexual crimes lack witness due to their private and isolated nature [11]. In these scenarios, Jurors are often reluctant to rely solely on the victim’s account without additional evidence [12]. This dependence creates a justice gap, as many credible cases are dismissed or result in exonerations due to the absence of external witnesses [13].

The media portrays DNA as the conclusive factor in sexual assault prosecutions. However, less than 1% of criminal prosecutions rely on DNA evidence [14]. In many adult sexual assault cases, prosecutors build a case on behavioral, circumstantial, and testimonial evidence supported by trauma-informed investigative methods [15].

Beyond the need for evidence, bias in society often impedes the prosecution of sexual abuse cases. Victims usually face stereotypes about their appearance, behavior, or past relationships, which may be used to cast doubt on their integrity [16,17,18]. In these circumstances and challenges, it is necessary to explore how cases of sexual crimes can be successfully prosecuted without the availability of direct forensic evidence.

The research on sexual offenses indicates a large discrepancy between the presence of forensic evidence and the effective prosecution of criminals [19]. Although most studies point to the requirement of physical and biological traces, new research indicates that behavior, psychology, and digital evidence can also prove to be crucial [20]. Nevertheless, despite a widening base of knowledge, academic consensus is still divided and somewhat descriptive in nature [21]. This section critically reviews existing literature within four thematic areas—legal impediments, forensic limitations, psychological factors, and digital options—to highlight existing gaps and justify the current review [22].

Internationally, sexual offenses continue to be the least effectively prosecuted crimes [23]. Conviction rates remain very low in most jurisdictions, largely because of the lack of concrete evidence. Victim-centered approaches and policy changes notwithstanding, prosecutorial results continue to rely considerably on the availability of concrete evidence [24].

Cross-country comparisons between developed and developing countries reveal differentiated procedural expectations. While others utilize trauma-informed practices to enhance testimony credibility, others still use medico-legal evidence as the main predictor of guilt [25]. Such a reliance creates a forensic gap that ignores the evidentiary value of behavioral, testimonial, or digital evidence [26]. In general, international legal systems are still bound by conventional evidentiary hierarchies, which emphasize the imperative to search for adaptive prosecutorial models that can maintain convictions even without physical evidence [27].

Forensic science has revolutionized contemporary criminal justice by offering objective means of connecting suspects to crime [28]. Physical and biological evidence, like DNA, hair, and body fluids, have long made prosecutors’ cases more powerful [29]. However, few, if any, sexual assault cases depend exclusively on DNA evidence [30]. This excessive dependence on physical evidence has also generated unrealistic hope among juries, resulting in what is so-called the “CSI effect”, where scientific evidence is overestimated and testimonial evidence is devalued [31].

High-tech forensic methods such as trace DNA and contact-based recovery techniques have enhanced detection sensitivity, but their use is still variable from one jurisdiction to another [32]. In addition, the lack of trained medical and forensic staff remains a hindrance to collecting and preserving evidence on time [33]. It is on this basis that these findings show a paradox: technological advancement increases the value of forensic evidence, but institutional constraints continue to limit its influence [34]. Thus, there is an increasing necessity for unifying evidentiary models that weigh scientific and circumstantial evidence without favoring one type of evidence over the other [35].

A convergent body of evidence from psychology and neuroscience points to the impact of trauma and memory on witness credibility in sexual offense cases [36]. Psychological evidence indicates that trauma impacts recall, leading to delayed or dissociated disclosure that can be taken as dishonesty [37]. Some contend that stress-related distortion in memory complicates the consistency of testimony, rendering judicial interpretation challenging [38]. The convergence of these views signifies the challenge in translating psychological effects into the legal process.

Researchers have further revealed how implicit gender bias and myths influence juror judgments, frequently precipitating victim-blaming [39]. These biases exist in the face of common advocacy for trauma-informed interview practices aimed at assisting victims throughout the investigation and testimony [40]. There is consensus in the literature that without expert psychological testimony, jurors commonly misinterpret inconsistencies as fabrication instead of trauma-based responses [41]. Therefore, forensic psychology provides not only contextual insight but also evidentiary power, bridging interpretive gaps in the absence of physical evidence. Fewer empirical studies, however, are available to quantify how such testimony contributes to conviction rates—a central gap confronted by the current review [42].

The increasing digitalization of communications has created new opportunities for collecting evidence in the prosecution of sexual crime [43]. Metadata, GPS data, and social-media activity can establish timelines, verify presence, and rebut assertions of consent [44]. Such digital trace evidence transcends the older forensic paradigms and has become critical to modern legal cases.

There are still issues with admissibility, chain of custody, and the technical proficiency of law enforcement officers [45]. In most instances, digital evidence’s potential is lost due to inappropriate handling or procedural ignorance. As much as its value is appreciated, there are a few systems that combine digital data with psychological or behavioral signs to create holistic prosecutorial strategies [45]. This underscores the pressing need for standard protocols and interdisciplinary training to make digital evidence more credible and acceptable in court.

In general, the study suggests that the successful prosecution of sexual offenses without physical evidence is contingent upon integrating forensic, psychological, and digital methods into a seamless legal framework [46]. Earlier research is likely to explore these components in a vertical fashion, without illustrating how they can coordinate to enhance prosecutorial evidence [47]. This review seeks to bridge that conceptual gap by integrating current findings, unearthing procedural and perceptual deficits, and suggesting integrative methods that promote conviction reliability despite the absence of physical evidence [48].

Physical evidence is the foundation of crime investigations, and the absence of such evidence weakens the prosecution’s argument. Physical evidence tends to explain how a crime occurred and identify and link a victim or a suspect to the scene of the crime [49]. It is also helpful in exonerating an innocent [50]. Physical injuries such as anal trauma, genital trauma, and traumatic lesions on the body, DNA evidence, and other identifiable markers are undeniable proof that a crime happened and ultimately provide a strong narrative for the jury to follow [51,52]. Popular media has shaped a perception that forensic evidence is a standard and essential component of criminal trials, so that an indirect approach may fall short of jury expectations [53,54,55].

The absence of physical evidence allows the defense to introduce reasonable doubt, which may be used to influence the jury. The defense might try to prove that the act was consensual or did not occur at all by arguing that there are no DNA or visible injuries [56]. This weakens the credibility of the prosecution’s case, highlighting the importance of other forms of evidence to fill this void.

Developments in forensic science are progressively addressing these challenges through innovative techniques to detect previously elusive forms of evidence. Investigators can now recover and analyze trace amounts of DNA left by mere contact with a surface due to the development of Touch DNA technology [56,57,58]. However, advancements in investigative tools, techniques, and methods offer hope. Detailed interpretation by experts and proactive education of jury members, ensuring that they understand the importance and limitations of such evidence, is needed to use innovative methods effectively.

Delayed reporting is a widespread issue in sexual crimes, deep-rooted in the profound emotional, psychological, and social challenges victims face [59]. Due to fear of judgment, potential revenge from their assailant, or societal humiliation, victims often delay coming forward to report. This hesitancy is intensified by the overwhelming trauma linked with the incident, leaving victims struggling with feelings of confusion, mistrust, and shame [60]. These delays result in the loss of important forensic evidence like bodily fluids, injuries, etc., which reduces the prosecution’s ability to establish a convincing timeline of events [61].

The psychological outcomes of trauma impact the reporting of a crime. Victims may internally self-blame or fear being ignored by authorities, which leads to silence [62]. This silence and delay in reporting are often misinterpreted by judges and jury members, who may wrongly associate the absence of timely disclosure with lying or fabrication. Such delusions can result in an unjust bias against victims, further complicating their search for justice.

The absence of physical evidence often leads to the outcome that a court trial hinges on the perceived integrity of the victim’s testimony against that of the accused. Situations like “she-said or he-said” present a challenge as jury members assess contradictory narratives without corroborative evidence [63]. This dependence on subjective evaluations can result in acquittal if the defense effectively establishes reasonable doubt.

Biases and stereotypes significantly influence judicial outcomes in sex crime cases, often to the detriment of fairness [64,65,66,67]. Jurors frequently hold preconceived notions about how a real victim should act, expecting behaviors such as visible emotional distress, immediate reporting of the crime, or consistent accounts of the incident [68]. When victims deviate from these expectations, perhaps due to trauma, fear, or other personal reasons, their credibility is unfairly called into question, diminishing the strength of their testimony [69].

Similarly, stereotypes about offenders can shape case outcomes. Defendants who do not conform to the perceived image of a typical sex offender, whether due to their demeanor, appearance, or social standing, often benefit from implicit biases. These biases can make jurors less inclined to believe the accusations against them, creating an uneven playing field [70,71]. For example, individuals perceived as respected community members, professionals, or those with no prior criminal history may be viewed as less likely to commit such crimes, regardless of the evidence presented.

In the majority of cases involving sexual crimes, the sole witness is the victim, which makes corroboration of their account nearly impossible [72]. The prosecution’s case rests on the narrative of the victim in the absence of supporting testimony and physical evidence [73]. This creates vulnerabilities as a defense strategy targeting to undermine the credibility of the victim by highlighting discrepancies in their account or aggressively conducting cross-examination [74].

The lack of corroborative evidence puts significant pressure on victims to recount events with absolute accuracy, even during the intense stress of courtroom proceedings [75,76]. However, the conditions through which the victim suffered can affect the recall of memories, which leads to inconsistent or fragmented details [77,78,79]. Instead of understanding these inconsistencies as a result of trauma, they are often used to discredit the victim. This weakens the case and creates more emotional discomfort for the victim.

The behavior of the victim after the incident, digital communication, or social media activity often holds a pivotal role in sexual crime incidents where physical evidence is not present [80,81]. This kind of evidence can provide vital context in assisting the jury members to understand the dynamics of criminal activity and the relationship between the perpetrator and the victim. For instance, behavioral evidence such as patterns of coercion, intimidation, grooming, or manipulation can demonstrate the power imbalance at play and provide a clear image of the events leading up to and following the incident.

Prosecutors may utilize circumstantial evidence in their strategies to strengthen cases. Emails, text messages, or social media communications exchanged before and after the crime can disclose the offender’s intent, the victim’s lack of consent, and efforts to control or threaten the victim [82]. Behavioral experts can offer expertise to describe why victims may show reactions that the jury might find counterintuitive, like the absence of visible distress, delay in reporting, or continued communication with the offender [83]. These insights help fill the gap between the psychological realities of trauma and jury expectations.

Dejong and Rose [84] reviewed 115 cases of child sexual assault with convictions. Only 23% of all cases have physical evidence. Among 85 cases without physical evidence, in 67 cases the criminals were convicted. The successful prosecution in these cases results from the quality of verbal evidence and the effectiveness of the victim’s testimony.

Forensic psychology has significantly developed the understanding of trauma and its profound effects on victims of sexual crime and violence [85]. Investigators and legal professionals can create a safe environment that reduces retraumatization by using trauma-informed interviewing techniques. These methods are intended to aid victims in recalling details of the incident more effectively. This results in testimonies that are both consistent and coherent, thus consolidating the case of prosecution.

Psychologists play an important role as expert witnesses in court trials by providing insights into trauma responses like dissociation, memory fragmentation, or the freeze reaction during or after a sexual assault [86]. The psychological assessments of the accused or suspect can reveal behavioral patterns consistent with profiles of known sexual offenders.

In today’s digital age, electronic evidence has become a key factor in prosecuting sex crimes, offering critical information that can validate victim accounts and provide a comprehensive timeline of events [87]. Different forms of digital communications, such as text messages, emails, and social media interactions, often disclose patterns that can establish the intent of the perpetrator and directly counter claims of consensual activity, such as threatening messages sent before or after the incident, which can determine a calculated effort to intimidate and silence the victim [88].

Besides direct communication, digital evidence consists of metadata such as device usage logs, geolocation data, and timestamps [89]. This kind of evidence can confirm the presence of both the victim and offender at specific locations, providing a form of corroboration that strengthens the prosecution’s case in the absence of physical evidence.

The effective usage of digital evidence in court trials depends on rigorous adherence to legal protocols for its collection, preservation, and presentation. Any mismanagement or apparent tampering can pave the way for defense challenges, leading to a decline in admissibility [90]. Therefore, law enforcement personnel and legal experts require specialized training to guarantee the legitimacy and integrity of digital evidence. This consists of understanding chain-of-custody protocols, using forensic tools to excerpt data, and presenting findings in a way that is acceptable and understandable by the jury.

Expert witnesses play an important part in presenting complex scientific, psychological, and legal concepts in a way understandable to jurors. Their testimony clarifies misconceptions and increases the credibility of the victim’s claims [91]. In the same way, forensic analysts contribute by interpreting circumstantial evidence, such as digital traces, patterns of communication, or behavioral dynamics, to explain the comprehensive framework of the crime [92]. Such analysis and expert testimony can help shift the focus of the jury from the lack of physical evidence to a wide-ranging view of the case, highlighting intent and patterns over tangible proof.

The influence of expert testimony depends profoundly on how it is presented. Experts must extract complex information into clear, relatable explanations that are understandable to a common audience [93]. Ambiguous interpretations and excessive usage of technical language can decrease the effectiveness. To ensure desired results, experts should directly address the misunderstandings the jury might hold.

Prosecuting sexual crimes without physical evidence demands a multifaceted approach that links the gap between legal strategy, psychological insight, and juror perception. The neoteric literature underscores that trauma has an acute influence on victim memory and reporting patterns, which can be misinterpreted as inconsistencies in testimony [15,94]. Preparation for courtroom testimony and trauma-informed interviewing can help mitigate these misunderstandings, thus enhancing credibility in the eyes of the jury.

Non-physical evidence can be powerful when presented cohesively. Eyewitness statements, digital communications, timelines, and the defendant’s contradictory statements can serve as corroborative elements. Expert testimony explaining the neurobiology of trauma helps jurors understand victims’ behavior, for example, fragmented recall or delayed reporting that might be taken suspiciously [95].

Bias reduction is a serious component. Research on rape myths and DARVO reveals that justice professionals may instinctively adopt misconceptions that shift blame from the perpetrator to the victim. Specialized training for prosecutors and investigators can counter these biases and encourage evidence-driven decision-making. Employing trauma-informed practices in judicial processes and law enforcement organizations is important to addressing the exceptional requirements of sexual crime victims and guaranteeing a more unbiased justice system [25]. These practices are grounded in an understanding of the psychological effects of trauma, which can greatly influence how victims communicate, recall, and respond to their experiences. By doing so, trauma-informed methods aim to reduce traumatic influence and improve the accuracy and reliability of victim participation.

Officers trained in these practices understand how trauma affects memory and behavior, allowing them to establish safe and supportive surroundings for victims. They may ask open-ended questions, allow more time for responses, and avoid leading or harsh, accusatory language and words. This approach makes victims feel heard and respected and enables the collection of detailed and accurate accounts necessary for building a strong case [96].

In judicial settings, measures like allowing the victim to give testimony via video link, using protective screens, or limiting face-to-face confrontation with the accused can reduce the stress and anxiety related to court appearances. This recognizes the emotional toll of reliving traumatic experiences in an adversarial and public setting, helping victims provide consistent and clearer testimony.

Beyond adaptations in procedures, trauma-informed practices also signal institutional empathy and foster trust in the justice system. Victims whose experiences are taken seriously and handled sensitively are likelier to come forward, cooperate with investigations, and remain involved throughout the legal process.

Special training for judges, both prosecutors and defense attorneys, is crucial to guarantee that sexual crime incidents are dealt with fairness, sensitivity, and with a complete understanding of their complexities. Such training should address critical areas such as dismantling common biases and myths about sexual violence and victims, considering trauma-related behaviors, and recognizing the evidentiary value of non-physical proof and evidence. This way, courtrooms can provide a more equitable dynamic, ensuring that victims are treated with respect while giving the jury precise, science-based information to guide their decisions.

Interdisciplinary collaboration between forensic scientists, legal experts, and psychologists can improve case preparation and the presentation of evidence. Forensic scientists can analyze and provide information from digital or circumstantial evidence, whereas psychologists can clarify trauma responses and behavioral patterns during trials.

Extensive societal change is important to eradicate the stigma around sexual violence and create an environment where victims can be supported in seeking justice. An important aspect of this change lies in public awareness campaigns intended to educate communities about the realities of sexual violence, the impacts of trauma, and the importance of victim testimony. These campaigns should address misconceptions that undermine a victim’s credibility, thereby reducing the prevalence of victim-blaming during investigations and trials.

Along with public education, integration of consent education and spectator intervention training into school curricula can nurture a culture of respect and accountability from a young age. Teaching students about affirmative consent, healthy relationships, and the dynamics of power and coercion helps them identify and challenge harmful behaviors. Spectator intervention training empowers individuals to step in and handle potentially dangerous circumstances, creating safer communities.

International and domestic multidisciplinary models demonstrate that collaborative efforts among forensic scientists, law enforcement, prosecutors, and victim advocates can greatly enhance investigative thoroughness and increase conviction rates [96,97]. These models show that coordinated case management, even in the absence of physical evidence, increases the chances of a successful prosecution.

These efforts can normalize conversations about sexual mishaps, encouraging individuals to report incidents and seek out help without any fear of judgment. When combined with trauma-informed legal and judicial practices, societal change driven by education and awareness can establish a healthy support system for victims and survivors while promoting prevention and accountability.

Prosecuting sex crimes without physical evidence is certainly challenging, but it is far from impossible. Through innovative approaches and systemic improvements, the judicial system can address these complications and improve consequences for survivors. Leveraging circumstantial and behavioral evidence allows prosecutors to present a complete picture of the crime. Expert witnesses, including forensic psychologists and analysts, play a crucial role in contextualizing and explaining trauma responses, interpreting non-physical evidence for the jury, and victim behavior. Using trauma-informed practices ensures that victims are treated with dignity and that they are heard in a supportive and fair environment. Legal reforms and public awareness initiatives challenge societal biases, reduce stigma, and encourage victims to report crimes. Balancing the pursuit of justice for victims with the protection of the rights of the accused requires an evidence-based approach rooted in empathy and education. Further progress in legal practices, forensic science, and societal attitudes can help alleviate the barriers posed by the absence of physical evidence. Hence, the judicial system can ensure that survivors of sexual abuse and violence receive the justice and support they deserve while upholding equity and fairness for both the victim and the accused.

H.U.R.: Writing—original draft. A.A.: Writing—review & editing. Z.S.: Literature review, Writing—review & editing, Visualization. H.M.A.M.: Supervision, Critical revision of the manuscript. M.I.: Writing—review & editing, Critical revision of the manuscript. H.F.: Writing—review & editing, Critical revision of the manuscript. R.U.: Literature review, Writing—review & editing. M.S.C.: Supervision, Validation. U.K.: Writing—review & editing. A.B.: Writing—review & editing. M.M.: Writing—review & editing.

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This research received no external funding.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.