Missing Person Cases Research Articles

Without a trace: Long-term missing women and girls and 'no-body' femicides from the Republic of Ireland.

Missing persons are a major part of everyday policing. However, some missing person cases can be highly emotive and challenging such as missing women and girls. Women who go missing have a greater risk of coming to harm. This study focused on 38 long-term missing women and girls from the Irish Republic from 1971 to 2023 of which 12 cases are now classified as homicides, and the whereabouts of the bodies remain unknown. The majority of cases are in Leinster with 25. Eight missing persons are under 18 years, and 22 are between the ages of 18 and 45 years. Domestic violence was a feature in five cases, involvement in a fight prior to disappearance in seven cases, and inconsistencies in statements by intimate partners and close family members regarding the victim's mental health were noted in seven cases. In nine cases, the personal belongings of the victim remained in the home. In seven cases, there was suggestive evidence that the victim entered water. These factors were seen in both the missing and classified homicide cases. The suicide narrative is heavily implied in many of these cases. A woman's mental health and stage of life such as pregnancy, childbirth and menopause can be exploited and used as an advantage to a potential killer. It is therefore paramount that missing women who are considered to have taken their own lives should be thoroughly investigated, with a special focus on cases where evidence suggests drowning and jumping from a height.

Non-invasive forensic identification of excavated human remains: capturing surface and internal fingerprints using optical coherence tomography.

Unidentified human remains are frequently found in missing person cases, necessitating identification for forensic purposes and to inform the next of kin. Traditional postmortem fingerprinting methods depend on intact surface fingerprints, which are often compromised by decomposition. A viable alternative is to use internal fingerprints(a blueprint of the surface fingerprint located just below the epidermis) instead. This study assessed the utility of Optical Coherence Tomography (OCT) as a means to record internal fingerprints from excavated human fingers. Conducted at the Amsterdam human taphonomic test site, the investigation comprised two longitudinal studies and two in situ burial scenarios. Human fingers were buried, excavated, and scanned using OCT at various time intervals.Internal fingerprints could be recorded up to 7 days longer than surface fingerprints, with a maximum of 10 days post-burial. These internal fingerprints provided higher minutiae counts, suitable for Automated Fingerprint Identification System (AFIS) searches. Additionally, in one case, fingerprints were successfully extracted after 13 weeks and 10 months of in situ burial. This demonstrates OCT's potential to enhance postmortem fingerprinting for identifying human remains in forensic investigations.

Kinship Verification Based on Intelligent Techniques: Survey

Kinship verification is the process of using observable characteristics, including facial features or other biometric data, to ascertain whether two people are familial related. Current approaches to kinship verification encounter multiple challenges, despite their significance in fields such as biometric security, family reunification, and forensic investigations. The most accurate way to confirm kinship is by DNA analysis, which is expensive, time-consuming, and invasive; in contrast, the traditional methods using manual comparison and facial recognition are more prone to human mistake. Visual verification of kinship among family members can be difficult to reliably rely on due to genetic variability, aging, and environmental influences. Automated methods that can reliably and efficiently confirm kinship using non-invasive methods are required, especially in situations where immediate identification is essential, like in the investigation of missing persons cases and disaster response. This study explores the use of different verification kinship techniques, ranging from various machine learning techniques reaching to up-to-date deep learning techniques. Finally, this study will discuss the datasets, preprocessing, methodology, advantages, disadvantages, and performance measures of selected state-of-the-art studies of kinship verification, and present the best technique used in kinship verification with the most related dataset. Index Terms— Kinship verification, Deep learning, Machine learning.

An exploration into why there is an overrepresentation of BAME people in missing person cases

An exploration into why there is an overrepresentation of BAME people in missing person cases

Salivary microbiome signatures of Poles and Serbians and its potential for prediction of biogeographic ancestry

Biogeographical ancestry analysis is valuable in forensic investigations, especially in missing person cases or crimes without eyewitnesses, as it helps to infer geographic origins from genetic markers. This approach enhances forensic efforts by providing essential clues for identifying individuals with limited direct evidence. Slavic-speaking populations are poorly distinguishable based on human genome variability. However, recent studies show that even populations with close biogeographic origin could be differentiated based on salivary microbiomes. Nevertheless, the salivary microbiomes of Slavs have not been characterized yet. Therefore, this study aimed to compare the composition of the salivary microbiomes of Western and Southern Slavs’ representatives. 16S rRNA libraries from salivary microbiomes of 40 Poles (Western Slavs) and 40 Serbians (Southern Slavs) were prepared via PCR and sequenced on the MiSeq FGx platform (Illumina), giving approximately 100,000 reads per sample. Bioinformatic and statistical analyses were performed to assess the alpha and beta diversity of microbiomes and determine the differences in the abundance of bacterial genera between the groups studied. Analyses of alpha (ACE, Chao1, Shannon, and Simpson) and beta (Jaccard and Bray-Curtis dissimilarity) diversities in the salivary microbiomes clearly distinguished between Poles and Serbians. Alpha and beta diversity metrics were significantly higher in the Serbian population. Fusobacterium, Lautropia, Porphyromonas, Actinobacillus, Capnocytophaga, and Kingella were the most significantly increased genera in Serbians, whereas Veillonella, Selenomonas, Megasphaera, and Atopobium were more prevalent in Poles. In summary, our study identified significant differences in the salivary microbiomes of Poles and Serbians, with distinct microbial signatures associated with each population. These findings highlight the potential of salivary microbiome analysis as a tool for predicting biogeographic ancestry. Nevertheless, further analysis extended to other Slavic-speaking populations is necessary to clarify this issue.

Spotting missing or wanted people: racial biases in prospective person memory

Searching for missing or wanted people is a crucial task in our society. Previous work on prospective person memory (PPM) has demonstrated that performance on this type of search task is worse relative to standard prospective memory tasks. Importantly, this process may be further affected by the race of the missing person, yet this has never been tested in laboratory settings. To test the effects of race on PPM, a convenience sample consisting primarily of self-identified Caucasian participants was asked to search for either a Caucasian or an Indian target person while judging the orientation of different Caucasian and Indian faces. Although the tasks were otherwise identical, 89% of Caucasian PPM targets were found while only 53% of Indian targets were found. Furthermore, relative to a control group with no PPM requirements, participants were slower and more error-prone when judging Indian faces relative to White faces, particularly if they were searching for an Indian face. We interpret these results as revealing other-race effects in prospective person memory, highlighting race as a critical factor for finding missing people. Importantly, this also emphasizes the need for real-world search efforts to factor in difficulty differences when people monitor for missing/wanted people from their own or different racial backgrounds. For example, media coverage of missing persons cases could perhaps be distributed more equitably by considering whether the missing person is from a racial minority in that region.

The urge to search: cognitive and affective drivers of citizen searches in missing person cases

ABSTRACT In missing persons cases, police often face citizen initiated searches. Though possibly beneficial (e.g., capacity), citizen involvement also carries risks (e.g., destroying evidence). It is important to manage searches, but often the police have no formal basis for cooperation and no legal means to impose restrictions. The police can only manage searches by exerting their influence at the behavioral level. Before behavioral interventions can be developed, it is necessary to understand the psychological drivers underlying citizen searches. Through a questionnaire (N = 627) based on Community Engagement Theory, Theory of Planned Behavior, and affective measures, we investigated what factors influence citizens’ intent to search. Intention related positively to affect, and beliefs about efficacy and usefulness. The only negative relationship found was for perceived authority. The results suggest that affect is a strong predictor of citizen involvement, and that strengthening perceived police authority offers opportunities to limit or redirect citizen searches where necessary.

Unraveling the patterns of critical contributory factors and flag-state affiliations linked with maritime incident outcomes

Maritime incidents are complex in nature and result from various factors. Although researchers have explored the factors influencing maritime safety, it is unclear how the critical contributory factor chains including flag-state associations, influence maritime incident outcomes, namely deaths, injury, and missing person cases. This paper applies a robust non-parametric Association Rules Mining (ARM) algorithm to an extensive marine incident database to identify critical patterns of key contributory factors and flag-state associations leading to different maritime incident casualty outcomes. The study dataset comprised 13,758 maritime incidents recorded between 2002 and 2015 in US territorial waters. This data was sourced from the Marine Information for Safety and Law Enforcement (MISLE) database system and served as the basis for analysis. A preliminary investigation revealed that low-weight passenger ships were most likely involved in maritime incidents. Further analysis established that, whereas Bahamas-registered vessels were highly likely to be involved in incidents associated with deaths, US-registered vessels were primarily related to injury-related incidents. Singaporean ships were often involved in missing-person incidents. Additionally, the results highlighted significant associations between ocean cruise vessels and existing medical conditions with deaths. Besides, passengers, towing service vessels, and crewmembers were identified to be highly associated with injury. Higher-order associations depicted that tank ships, fishing vessels, ship masters and crew members are likely to be involved in maritime incidents where missing persons are involved. Policies directed at eliminating/controlling the contributory factors identified to lead to a particular outcome to help reduce the occurrence or impacts of maritime incidents have been suggested.

Classifying missing persons cases: an analysis of police risk assessments using multi-dimensional scaling

ABSTRACT Missing persons cases present a complex challenge for law enforcement globally and require a nuanced understanding of their typologies. This study provides a comprehensive analysis of cases from the United Kingdom, from within a single police service, focusing on the alignment of police missing person risk assessment (RA) factors with existing typologies. Utilizing data exclusively from nearly 5000 police RAs, the study undertakes a multi-stage analysis, examining RA factors for congruence with established typologies and exploring data subsets based on gender, case outcomes, and risk gradings. Using Jaccard’s similarity coefficient and smallest space analysis (SSA), the study interprets and visualizes the cases to explore relationships. Results are reported using visual and descriptive statistics. Key findings include confirmation of alignment to existing typologies and research that has identified ‘unintentional – accidental/drift’ as the dominant missing person typology, identifying it in 65% of the cases. Notably, the typology was also the dominant theme in 45% of the cases resulting in a harmful outcome and 42% graded as high-risk. Categorical nuances are identified within subsets, with 47% of long-term missing and 63% involving men relating to the intentional – dysfunctional typology. 31% of the cases involving females, and 30% and 45% of the cases graded as medium and no apparent risk, respectively, were dominated by the ‘intentional – escape’ typology. We discuss how these findings can be used to improve the police RA process and guide initial risk grading and case prioritization enhancing the understanding and response to missing person cases.

Managing large volume data sets in the process of identifying missing persons: Contributions from the International Commission on Missing Persons.

The process of locating and identifying missing persons presents a complex challenge that hinges on the collection and comparison of diverse data sets. This commentary offers an overview of some of the difficulties and considerations associated with data management in the context of large-scale missing person identifications. Such complexities include the uniqueness of each disaster event, the response time to the event, the variable quality and quantity of data, and the involvement of numerous stakeholders, all of which contribute to the intricacies of data management. In addition, the paramount considerations of privacy and ethical standards further compound these challenges, especially when dealing with sensitive information such as genetic data. This commentary describes the integrated Data Management System (iDMS) developed by the International Commission on Missing Persons (ICMP) as one example of a comprehensive, freely available solution for data collection, storage, protection, and analysis in missing person cases. The various advantages of the system are discussed, including the system's interoperability among the diverse array of stakeholders involved. While the iDMS streamlines data management processes and therefore represents a significant advancement in the field of missing person identification, it is concluded that the pending issue extends beyond thesoftware tools to encompass the lack of political will among stakeholders to collaborate there remains a pressing need for all stakeholders involved in the identification process to commit to a mechanism that facilitates compatibility and interoperability if different tools are used in disaster victim identification (DVI) scenarios.

Emergent volunteerism in missing person cases — A Dutch case study

In missing person cases, police often face spontaneous searches by citizens. This study examined the involvement of police and citizens in a well-known Dutch case. It shows that the relationship between police and volunteers is not static, but changes over time. Initially, citizens are more quickly organized and take charge. As the investigation progresses, different types of volunteers are incorporated into the police structure. Citizens pose dilemmas regarding direction and information sharing, but provide valuable search capacity and expertise. The results show the importance of not opposing citizen initiatives, but rather making contact, establishing structure and coordinating efforts early on.

Evaluating the Time of Death (Post Mortem Interval, PMI) through Forensic Entomo-toxicological Investigations of Maggots and Flies

The estimation of the post mortem interval (PMI) is a critical component of forensic science, aiding investigations and resolving missing persons cases. This abstract explores the innovative approach of forensic entomotoxicological investigations, focusing on the analysis of maggots and flies in PMI estimation. Maggots and flies are key players in the decomposition process, and their lifecycles are closely linked to the stages of decay. Challenges and limitations, such as environmental factors and variable drug metabolism, are considered. Two compelling case studies exemplify the practical applications of forensic entomotoxicology in solving criminal cases and missing persons investigations.
 The primary goal of this paper is to provide guidance to knowledgeable researchers and investigators in the realm of forensic entomotoxicology. It underscores the need for a heightened focus on forensic Entomotoxicology, particularly in investigations involving the effects of drugs on the growth stages of insect development, for more accurate postmortem interval estimations, especially in cases involving decomposed remains. In conclusion, forensic entomotoxicological investigations of maggots and flies present a dynamic and invaluable approach to PMI estimation, promising to enhance the accuracy and reliability of forensic science in determining the timing of death.

The suitability of using domestic pigs (Sus spp.) as human proxies in the geophysical detection of clandestine graves.

Research in many forensic science fields commonly uses domestic pigs (Sus spp.) as proxies for human remains, due to their physiological and anatomical similarities, as well as being more readily available. Unfortunately, previous research, especially that which compares the decompositional process, has shown that pigs are not appropriate proxies for humans. To date, there has not been any published research that specifically addresses whether domestic pigs are adequate human proxies for the geophysical detection of clandestine graves. As such, the aim of this paper was to compare the geophysical responses of pig cadavers and human donor graves, in order to determine if pigs can indeed be used as adequate human proxies. To accomplish this, ground penetrating radar (GPR) and electrical resistivity tomography (ERT) responses on single and multiple pig cadaver graves were compared to single and multiple human donor graves, all of which are in known locations within the same geological environment. The results showed that under field conditions, both GPR and ERT were successful at observing human and pig burials, with no obvious differences between the detected geophysical responses. The results also showed that there were no differences in the geophysical responses of those who were clothed and unclothed. The similarity of the responses may reflect that the geophysical techniques can detect graves despite what their contents are. The study implications suggest that experimental studies in other soil and climate conditions can be easily replicated, benefiting law enforcement with missing persons cases.

Public/family concerns for providing DNA in missing persons cases: Paper 2: The main concerns raised and implications for policing policy

Identification of unidentified human remains, and long-term missing persons (LTMP) is imperative, allowing for missing persons to be reunited with their families, which could provide closure to families experiencing ongoing ambiguity surrounding the situation. However, identification remains problematic for several reasons, including the absence of DNA provision in the investigation. The research reported here is the second in a two-part series exploring public/family support for providing DNA in LTMP cases. In the first study, quantitative results showed that participants had concerns when asked if they thought there would be implications for a person providing DNA to police in LTMP cases. The aim of this second study was to explore further using qualitative methods the nuances and themes underpinning concerns for providing DNA in LTMP cases. Participants described their concerns about providing DNA in four hypothetical LTMP case scenarios (a child, an adult with dementia, a runaway 19-year-old adolescent, and an estranged adult). Through thematic content analysis, ten themes were identified. Nine themes run across all four LTMP case scenarios. The tenth theme was only observed in two scenarios; cases involving adolescents with a history of runaway, and in cases involving adults estranged from their family. Results showed public concerns differed according to LTMP case circumstances. Key findings point to public education about how DNA is used in LTMP investigations, the applicable legislation relating to police use of DNA in investigations and increasing public awareness around the benefits of DNA use in LTMP investigations. Potentional policy options are discussed that could guide the future development of nuanced police practice in different types of LTMP cases.

Unraveling crime scenes strand by strand: the forensic odyssey of Bruce Budowle.

Bruce Budowle speaks to Ashling Cannon, Journal Development Editor for BioTechniques, about advancements & challenges in forensic science. Budowle completed his doctorate in genetics at Virginia Tech (VA, USA) formally known as Virginia Polytechnic Institute and State University. He then went on to complete a postdoctoral fellowship at the University of Alabama at Birmingham (AL, USA) to study genetic risk factors for acute lymphocytic leukemia, diabetes and melanoma. Budowle was early in his career and hadn't spent much time in forensics at this stage, but in 1982 an advert caught his eye for a job with the FBI to develop genetic marker systems to identify people who have left biological evidence at crime scenes. Budowle spent 26years with the FBI and helped develop a plethora of genetic analysis methods. In 1985, it became a reality that DNA could be a signature for identifying people, and there were huge developments in DNA forensic analysis. In 2009, Budowle moved into academia and went to the University of North Texas Health Science Center (TX, USA), eventually becoming the Director of the Center for Human Identification, where he oversaw missing person and traditional crime cases, taught students and carried out fundamental and applied research. Budowle feels incredibly lucky to have had the resources, opportunities and academic infrastructure to learn and develop his knowledge. Budowle recently retired from academia and now spends his time building capacity for DNA forensics applications in Africa through the Department of Justice, with a well-established program known as the International Criminal Investigative Training Assistance Program (ICITAP) as well as with the non-government organization (NGO) DNAforAfrica.

Record-matching of STR profiles with fragmentary genomic SNP data.

In many forensic settings, identity of a DNA sample is sought from poor-quality DNA, for which the typical STR loci tabulated in forensic databases are not possible to reliably genotype. Genome-wide SNPs, however, can potentially be genotyped from such samples via next-generation sequencing, so that queries can in principle compare SNP genotypes from DNA samples of interest to STR genotype profiles that represent proposed matches. We use genetic record-matching to evaluate the possibility of testing SNP profiles obtained from poor-quality DNA samples to identify exact and relatedness matches to STR profiles. Using simulations based on whole-genome sequences, we show that in some settings, similar match accuracies to those seen with full coverage of the genome are obtained by genetic record-matching for SNP data that represent 5-10% genomic coverage. Thus, if even a fraction of random genomic SNPs can be genotyped by next-generation sequencing, then the potential may exist to test the resulting genotype profiles for matches to profiles consisting exclusively of nonoverlapping STR loci. The result has implications in relation to criminal justice, mass disasters, missing-person cases, studies of ancient DNA, and genomic privacy.

Involving citizens in urgent missing person cases. An application of the Theory of Planned Behaviour within District Criminal Investigations Teams

ABSTRACT This article examines the use of citizen participation by detectives in urgent missing person cases. Citizens can make a valuable contribution to finding a missing person, but this kind of assistance is often underutilised. We applied the Theory of Planned Behaviour to explore the extent to which attitudes, subjective norms, and perceived behavioural control influence detectives’ intentions to involve citizens and the detectives’ considerations underlying such intentions. To this end, a quantitative questionnaire was developed and administered to detectives from four regional police units. The best goodness-of-fit of the theoretical model was found for officers who deal with urgent missing persons cases regularly, but not often; for this group, the model explained 39 percent of the variance observed. The results show that intention is significantly related to detectives’ attitudes. Subjective norms had a significant predictive value, except for officers who encounter missing persons cases frequently. Perceived behavioural control had no significant effect. The study suggests that the choice to involve citizens is mainly attitude-driven, and is determined primarily by detectives’ personal affinity with citizen participation and their perception of its benefits. Perceived risks, such as damage to the investigation, have limited influence on decisions regarding citizen participation.

Cause of death in fatal missing person cases in England and Wales

Typically, fewer than 0.5% of missing incidents result in an individual being found deceased. Whereas previous research has examined the features of missing–homicide, missing–suicide and some aspects of missing–accident cases, this study sought to provide the first reliable estimates of the number and proportion of fatalities by all causes of death, specifically: suicide, accident, homicide and natural causes. Using data obtained on 615 fatal disappearances via Freedom of Information returns from 22 English and Welsh police forces covering a two-year period, this article presents data on the relative probability of fatality by cause of death for adults and children and for males and females. Overall, fatal outcomes are, thankfully, rare, occurring once in every 358 missing incidents. Some 98% of fatalities involved adults; just over 80% involved males. The findings affirm suicide as the largest single cause of death accounting for three-quarters of female fatalities and four in every five male fatalities. Although homicide was the least probable cause of death among male missing persons, females faced a roughly similar chance of dying as a result of an accident or homicide. The research indicates that estimates of probability can be used to inform investigative decision-making and scenario development, offering important context to the overall likelihood of an individual facing a fatal outcome. Further research is needed to replicate these findings.

Prototype of Missing Persons Android-Based Application at Abepura Police Station, Jayapura City, Papua.

Data from the Jayapura District Police shows that there was an increase in the number of missing persons in Jayapura City. In January 2022, there were 8 reports of missing persons, and this number doubled to 16 in March 2022. Currently, the police rely on reports from the public to find missing individuals. They then conduct direct checks in the field, confirm the reported characteristics, and contact the families. However, this method is not considered modern or efficient enough to handle the increasing number of missing persons cases. In this modern age, technological developments, especially in mobile applications, can offer more effective and efficient solutions. Therefore, a prototype application for missing persons based on Android was developed as an alternative to help address the issue of missing persons, especially in Jayapura City. The missing persons application underwent black box testing to ensure that its functions and inputs are working correctly, and the validation function was used to check its accuracy. The test results showed that the application is functioning well and can be used as a tool to help find missing persons in the city. However, continuous monitoring and improvement of the application are necessary to ensure that it remains effective in the long term.

Winthropping as an Investigative Tool in Clandestine Grave Discovery and Psychological Profiling

Missing persons cases are some of the hardest investigations to solve. The lack of forensic evidence impedes an investigation and critical time can be lost attempting to find the person or body. Recently, researchers have attempted to develop new approaches to help police in these types of investigations. The current paper continues research into Winthropping as a means of assisting police investigations when searching for clandestine, hidden graves and missing persons. A novel approach, using geocachers, to help inform Winthropping processes is outlined, and support gained through a survey of geocachers. The findings are then applied to a series of real-world homicides, including several serial killers. Analyses of gravesite locations in serial killer cases matched many of the features and properties outlined by geocachers. The results also indicate the potential of using Keatley and colleagues’ Winthropping as a psychological profiling as well as geographical profiling technique. Support was provided through the case of a murdered child who was later dumped. Recommendations for further research and application are provided.