AAFS 2027

Wednesday, February 17

7:15 am – 8:15 am

Presenter: 
Cynthia Cale, MSc 
DNA Mavens LLC/DNA Mavens Forensic Services, Inc.
Carney, TX

Learning Objectives: Attendees will learn how assumptions regarding contributor number and relatedness can influence probabilistic genotyping of complex DNA mixtures. This presentation will demonstrate how post-trial scientific review identified limitations in the original interpretation, resulting in amended laboratory conclusions and testimony corrections. It will emphasize the importance of technical review, quality assurance, and transparent communication when interpreting complex DNA evidence.

Impact Statement: This presentation will improve practitioners' ability to recognize analytical limitations in complex DNA mixtures involving related contributors and understand how those limitations can affect probabilistic genotyping results. It will promote scientifically rigorous interpretation, effective technical review, and transparent communication of forensic DNA evidence in reports and testimony.

DNA evidence recovered from a window in a sexual assault investigation became a central issue in a pretrial admissibility hearing and subsequent jury trial. The evidentiary sample was interpreted using probabilistic genotyping after being designated as a four-person mixture, and the resulting likelihood ratio was presented as support for the proposition that the defendant contributed to the DNA profile. Following a defense challenge to the interpretation, the trial court admitted the evidence, and the jury ultimately returned a guilty verdict.

After trial, concerns regarding the interpretation were independently reviewed. The laboratory re-evaluated the analytical documentation, interpretation process, and testimony and determined that relatedness among multiple first-degree relatives had not been adequately incorporated into the interpretation of the evidentiary sample. The laboratory concluded that the original number of contributors should have been designated as "four or more," placing the sample outside the laboratory's validated interpretation limits for probabilistic genotyping. As a result, the laboratory issued an amended report replacing the original interpretation with the conclusion that the DNA mixture was too complex for interpretation and formally corrected portions of the analyst's testimony. The court subsequently declared a mistrial and vacated the jury's verdict.

This case illustrates how contributor number determination, relatedness, degradation, and allele sharing are interdependent analytical considerations that may substantially influence probabilistic genotyping. It further demonstrates that post-trial quality review can identify scientific limitations not fully recognized during the original interpretation and underscores the importance of reassessing foundational analytical assumptions when new information becomes available. 

Wednesday, February 17

7:15 am – 8:15 am

Presenter: 
Morgan P. Tart, MS 
North Carolina State Bureau of Investigation
Raleigh, NC

Learning Objectives: Upon completion of this presentation, attendees will be able to: (1) recognize the crime scene indicators associated with a clandestine grave involving an atypical vertical burial; (2) evaluate crime scene documentation, excavation, and recovery techniques used to preserve evidence in a vertical clandestine burial; and (3) apply lessons learned from this case to improve investigative decision-making and evidence preservation during future clandestine grave recoveries. 

Attendees will examine the crime scene investigation of a homicide involving a rare vertical clandestine burial. Through a review of the scene response, documentation, excavation, evidence recovery, and investigative findings, participants will gain practical insight into the challenges associated with recovering human remains from an atypical burial context. The presentation will highlight lessons learned that can be applied to future clandestine grave investigations and emphasize the importance of meticulous crime scene processing in supporting successful investigative and prosecutorial outcomes.

Impact Statement: Clandestine graves present unique challenges that require careful scene assessment, documentation, and recovery to preserve forensic evidence and maintain investigative integrity. This presentation contributes to the forensic science community by examining the investigation and recovery of a rare vertical clandestine burial, highlighting practical lessons that can improve crime scene recognition, excavation strategies, and evidence preservation. By sharing the investigative approach, challenges encountered, and lessons learned, this presentation aims to enhance the preparedness of forensic practitioners who may encounter atypical clandestine burials and reinforce the importance of meticulous crime scene processing in supporting successful investigative and judicial outcomes.

On September 21, 2020, the North Carolina State Bureau of Investigation (NCSBI) responded to assist the Sampson County Sheriff's Office with the investigation of a reported homicide involving a missing 23-year-old male. Family members searching the property discovered what appeared to be a human leg protruding from freshly disturbed soil within a wooded area behind the victim's residence. Subsequent crime scene examination revealed an atypical clandestine grave in which the victim had been buried in a vertical position rather than the more commonly encountered horizontal orientation. Following systematic excavation and recovery operations, the victim was identified, and the death was later determined to be a homicide resulting from multiple sharp force injuries.

This presentation reviews the crime scene investigation from the initial response through documentation, excavation, evidence recovery, and investigative follow-up. Particular emphasis is placed on the challenges presented by the vertical burial configuration, including scene assessment, recognition of grave characteristics, photographic documentation, excavation strategy, preservation of spatial relationships, and recovery of the decedent while maintaining evidentiary integrity. The importance of multidisciplinary coordination among crime scene investigators, law enforcement, forensic pathologists, and other forensic personnel will also be discussed.

In addition to describing the investigative process, this case highlights practical considerations for responding to atypical clandestine burials and emphasizes how careful scene documentation and methodical recovery contributed to the successful investigation and subsequent prosecution. The suspect ultimately confessed to the homicide, describing the assault, concealment of the victim within the vertical grave, and efforts to avoid detection. The defendant later entered a guilty plea to second-degree murder in Sampson County Superior Court and received an active sentence of 300 to 372 months imprisonment.

Although most clandestine burial investigations involve more conventional body positioning, this case demonstrates the importance of adapting established crime scene and recovery techniques to unusual burial contexts while maintaining accepted forensic standards. The lessons presented are intended to improve preparedness, evidence preservation, and investigative decision-making for forensic practitioners who may encounter atypical clandestine graves during future homicide investigations. 

Wednesday, February 17

7:15 am – 8:15 am

Presenter: 
Amy L. Patton, PhD
North Louisiana Criminalistics Laboratory
Raleigh, NC

Learning Objectives: After attending this presentation, attendees will understand how communication between toxicology, drug chemistry, medicolegal death investigation, and law enforcement guided the progression of a complex death investigation. Attendees will be able to identify situations in which new investigative information should prompt re-evaluation of toxicological findings and appreciate how complementary forensic disciplines can collectively resolve cases that no single discipline could solve independently.

Impact Statement: This presentation highlights a practical model for interdisciplinary collaboration in forensic casework. By demonstrating how sequential communication and targeted analytical follow-up changed the interpretation of an initially unresolved death, attendees will gain strategies for strengthening collaboration among laboratories, death investigators, and law enforcement when encountering emerging drugs or unexpected analytical findings.

A single analytical result rarely resolves a complex death investigation. Rather, meaningful conclusions often emerge through collaboration among forensic disciplines, with each new finding directing the next stage of investigation. This case illustrates how communication between toxicology, drug chemistry, medicolegal death investigation, and law enforcement transformed an initially unresolved death investigation into the identification of a novel synthetic opioid and ultimately altered the certified manner of death.

An adult male was discovered deceased, and routine postmortem toxicology identified several commonly encountered therapeutic and impairing drugs. While these findings contributed to the overall interpretation, they did not adequately explain the death in light of the decedent's medical history.

Subsequently, investigators questioned whether scene evidence might provide additional context and submitted recovered tablets for forensic drug analysis. Drug chemistry identified the tablets as containing the emerging synthetic opioid N-Propionitrile chlorphine ("cychlorphine"), providing toxicology with a specific analytical target that had not previously been considered. Following acquisition of a reference standard, retrospective review of the original analytical data suggested the presence of cychlorphine in the decedent. Confirmatory testing by an independent reference laboratory verified the finding.

The combined interpretation of toxicology results, drug chemistry findings, investigative information, and medical history resulted in revision of the certified manner of death. More importantly, the case demonstrated that no single discipline possessed sufficient information to resolve the investigation independently. Each analytical and investigative finding informed the next step, ultimately producing a conclusion that would not have been possible through isolated laboratory testing.

This case emphasizes the value of sustained communication among forensic practitioners, the importance of revisiting initial interpretations when new evidence becomes available, and the critical role of interdisciplinary collaboration in recognizing emerging synthetic opioids and accurately interpreting complex medicolegal deaths.

Thursday, February 18

7:15 am – 8:15 am

Presenter: 
Kelly Crockett, MSFS 
Embry-Riddle Aeronautical University
Prescott, AZ

Learning Objectives: Attendees will learn how the Embry-Riddle Aeronautical University Cold Case Task Force applies an interdisciplinary investigative methodology to unresolved aviation disappearances by integrating Open-Source Intelligence (OSINT), aviation expertise, human factors, forensic psychology, geographic profiling, flight simulation, and geospatial technologies. Participants will be able to identify how modern forensic methodologies can be used to generate evidence-based investigative hypotheses, prioritize search areas, and supplement historical missing aircraft investigations using technologies unavailable during the original investigation.

Impact Statement: This presentation demonstrates how multidisciplinary collaboration between forensic scientists, aviation professionals, behavioral scientists, engineers, and student investigators can provide new investigative opportunities in historical missing aircraft cases. The investigative approach presented offers a practical, evidence-based model that may improve investigative performance, optimize future search strategies, and ultimately contribute to improved outcomes for agencies and families seeking answers in unresolved aviation disappearances.

On December 6, 1992, four young adults departed Santa Barbara, CA, aboard a routine general aviation flight bound for Palo Alto and were never seen again. More than 30 years later, the aircraft and its occupants remain missing despite extensive search efforts, making the case one of California's longest unresolved aviation disappearances. The flight carried pilot Kevin Clarke (31), his fiancée, Nancy Branch (29), and married couple Alan Stewart (29) and Amy Haxton Stewart (31).

This presentation highlights the ongoing work of the Embry-Riddle Aeronautical University Cold Case Task Force, an interdisciplinary collaboration of faculty and students representing forensic science, aviation, forensic psychology, aviation human factors, engineering, intelligence analysis, and geospatial technologies. Using this case as a proof of concept, the presentation demonstrates a structured multidisciplinary investigative approach that integrates historical evidence reconstruction, OSINT, aviation behavioral analysis, geographic profiling, predictive flight modeling, and modern remote sensing technologies to generate evidence-based investigative hypotheses applicable to unresolved aviation cold cases.

The investigation began with a comprehensive reconstruction of the original case using National Transportation Safety Board records, archived weather observations, publicly available aviation documentation, historical media accounts, and Federal Aviation Administration resources. Through OSINT research, investigators reconstructed two previously documented flight routes flown by the pilot to better understand habitual navigational preferences and aeronautical decision-making. These findings are being evaluated alongside documented meteorological conditions, including coastal cloud ceilings, visibility, winds, and precipitation recorded on the day of the disappearance.

Drawing upon established principles of aviation psychology, human factors, and aeronautical decision making, the Task Force is evaluating the working hypothesis that historical search efforts may have emphasized areas immediately adjacent to the California coastline and that pilot decision-making under deteriorating visual meteorological conditions may have resulted in an alternate route not previously prioritized. Geographic profiling techniques, adapted from forensic investigative practices, are being used to integrate behavioral, environmental, and navigational variables to identify probabilistic search corridors rather than relying solely upon historical search grids.

The next phase of the investigation will utilize flight simulation to recreate documented weather conditions, aircraft performance, and plausible pilot decision points. Resulting flight trajectories will be evaluated using contemporary satellite imagery, Geographic Information Systems (GIS), historical aerial photography, and remote sensing technologies to identify areas warranting additional examination.

While centered on a single unresolved disappearance, this case demonstrates how advances in forensic science, aviation research, behavioral science, geospatial technologies, and collaborative university partnerships can supplement historical investigations without replacing the original investigative record. Consistent with the conference theme, Around the World and Beyond, this presentation illustrates how forensic science continues to expand beyond traditional terrestrial crime scenes into aviation, maritime, and other remote environments where multidisciplinary investigative approaches may generate new opportunities for discovery and, ultimately, provide long-awaited answers for families of the missing.

Thursday, February 18

7:15 am – 8:15 am

Presenters: 
Anne Katy Fares, MD 
Instituto Médico-Legal Afrânio Peixoto
Civil Police of the State of Rio de Janeiro
Rio de Janeiro, Brazil

C A. Simões, MD 
Instituto Médico-Legal Afrânio Peixoto (IMLAP),
Civil Police of the State of Rio de Janeiro
Rio de Janeiro, Brazil

Alfredo Maio, MD 
Instituto Médico-Legal Afrânio Peixoto (IMLAP)
Civil Police of the State of Rio de Janeiro
Rio de Janeiro, Brazil

Paula Mota, MSc 
Instituto Médico-Legal Afrânio Peixoto (IMLAP)
Civil Police of the State of Rio de Janeiro
Rio de Janeiro, Brazil

Renata Lopes de Oliveira, MD 
Instituto Médico-Legal Afrânio Peixoto (IMLAP)
Civil Police of the State of Rio de Janeiro
Rio de Janeiro, Brazil

Camila Cheble, MD 
Instituto Médico-Legal Afrânio Peixoto (IMLAP)
Civil Police of the State of Rio de Janeiro
Rio de Janeiro, Brazil

Learning Objectives: This presentation will enable participants to recognize atypically early generalized rigor mortis, distinguish it from cadaveric spasm based on scene chronology, external examination, and autopsy findings, and understand the proposed mechanisms that may accelerate rigor mortis following intense muscular exertion and physical restraint. These concepts may improve the interpretation of unusual postmortem findings during forensic death investigations.

Impact Statement: This presentation contributes to forensic pathology by documenting an exceptionally rare and well-defined case of ultra-rapid generalized rigor mortis with a precisely documented chronology. The case highlights the importance of recognizing atypical postmortem changes, distinguishing accelerated rigor mortis from cadaveric spasm, and interpreting these findings within the context of the investigative history and autopsy. By expanding the discussion of an uncommon tanatological phenomenon, this presentation may improve forensic death investigation and stimulate further research into the mechanisms underlying accelerated rigor mortis.

Introduction: Rigor mortis results from depletion of muscular Adenosine Triphosphate (ATP) and is typically preceded by primary flaccidity, developing progressively over the first hours after death. Complete generalized rigor mortis occurring within 20 minutes is exceptionally rare and raises questions regarding its underlying pathophysiological mechanisms and its differential diagnosis with cadaveric spasm.

Case Report: A 31-year-old man developed severe psychomotor agitation with intense muscular exertion, violently resisting police intervention and engaging in a prolonged physical struggle that prevented voluntary placement into a police vehicle. Owing to persistent resistance, physical restraint and a Conducted Electrical Weapon (CEW) were employed to facilitate transportation to the medicolegal institute for forensic examination. According to the documented chronology, the individual was placed alive in the police vehicle. Upon arrival at the medicolegal institute, following an approximately 20-minute transport, death verification was performed. The external examination immediately demonstrated complete generalized rigor mortis involving the jaw, neck, trunk, and all extremities, sufficiently established to preserve the body posture assumed during transport. Subsequent autopsy confirmed generalized rigor mortis and revealed tongue laceration with blood aspiration, establishing asphyxia secondary to blood aspiration as the cause of death.

Discussion: The presence of complete generalized rigor mortis of this intensity within such a short documented interval is exceptional. Intense muscular activity related to psychomotor agitation and prolonged physical struggle, combined with physical restraint and CEW exposure, may have accelerated ATP depletion, further aggravated by hypoxia, metabolic acidosis, and sympathetic activation. Although the autopsy established the cause of death as asphyxia secondary to blood aspiration, this mechanism alone does not explain the unusually rapid onset of rigor mortis. Cadaveric spasm was considered in the differential diagnosis but could not be confirmed because of the generalized distribution of the rigidity.

Conclusion: This case documents an exceptionally early and intense onset of complete generalized rigor mortis, observed during death verification within a documented maximum interval of approximately 20 minutes between the last confirmed observation of life and the initial examination of the body. The report contributes to the understanding of accelerated rigor mortis and its distinction from cadaveric spasm, highlighting the importance of recognizing atypical postmortem changes during forensic death investigation.

Friday, February 19

7:15 am – 8:15 am

Presenters:
Maria do Carmo Gargaglione, MBA 
Ministério Público do Rio de Janeiro
Rio de Janeiro, Brazil

Eline Coqueijo Portela, MBA 
Ministério Público do Rio de Janeiro
Rio de Janeiro, Brazil

Caio Oliveira de Azevedo
Ministério Público do Rio de Janeiro
Rio de Janeiro, Brazil

Learning Objectives: Participants will understand how high-precision 3D scanning technology can be applied at scale for complex criminal investigations, particularly in police operations resulting in multiple casualties. Practical methodologies for image capture, 3D data processing, and ballistic analysis through 3D models will be presented, demonstrating how these tools enable precise reconstruction of confrontation dynamics and injury identification. Furthermore, participants will learn about the critical role of independent forensics in external oversight of police operations, understanding how forensic technology can ensure rigorous, transparent investigations in compliance with human rights standards. The Operation Contenção case study (121 victims, 334 body scans) will provide practical and replicable examples for similar contexts in other jurisdictions, highlighting the operational, technical, and institutional challenges of large-scale forensic investigation.

Impact Statement: The presentation by the Digital Evidence and Technology Division/ Public Prosecutor's Office of Rio de Janeiro (DEDIT/MPRJ) will demonstrate to the international forensic community that 3D scanning technology is not only viable for isolated cases, but can also be implemented on a large scale. Processing 334 body scans from 121 victims in a single operational event sets an important precedent: 3D technology is practical, replicable, and economically feasible for large-scale investigations. Expected impact: It will encourage other jurisdictions to invest in 3D scanning infrastructure, knowing that a proven model for mass implementation exists.

Context and Challenge: On October 28, 2025, a joint operation by Rio de Janeiro's Civil and Military Police in the Alemão and Penha Complexes resulted in 121 deaths, becoming the deadliest police operation in the state's history. Under supervision of ADPF 635 (a determination by the Brazilian Supreme Court) and in compliance with the Inter-American Court of Human Rights, the MPRJ was required to conduct independent forensics on all victims. This unprecedented challenge demanded a technical, objective, and scalable approach ensuring rigorous investigation, transparency, and compliance with human rights standards.

Methodology and Technology: The DEDIT of MPRJ led the independent forensic investigation using high-precision 3D scanning technology (Eyes Cloud 3D) integrated with a digital evidence management platform (Axon Evidence). A team of 8 professionals — medical examiners, technicians, and forensic assistants — attended all autopsies at the Afrânio Peixoto Medical-Legal Institute, conducting 334 body scans of the 121 victims. Three-dimensional models were generated from high-resolution videos and photographs, enabling detailed analysis of each injury, projectile trajectory, and compatibility with armed confrontation reports.

Results and Impact: Processing 334 body scans at scale demonstrated the viability, efficiency, and reliability of 3D technology for complex forensic investigations. The 3D models enabled: (1) precise mapping of projectile trajectories and injury patterns; (2) integrated analysis of multiple victims with technical consistency; (3) objective and re-analyzable evidence documentation; (4) secure and encrypted storage on cloud platform; and (5) compliance with judicial determinations for independent forensics. Final reports were submitted to the Supreme Court, contributing to investigations of potential police intervention abuses.

Significance for Forensic Sciences: This case study establishes an international precedent for forensic investigations in large-scale police operations. It demonstrates that 3D technology is not merely viable for isolated cases but essential for ensuring rigorous, transparent investigations compliant with human rights standards in urban violence contexts. The integration of 3D scanning, three-dimensional ballistic analysis, and secure digital evidence storage provides a replicable model for other jurisdictions facing similar challenges.

Conclusion: Operation Contenção represents a historic moment where forensic science, technology, and human rights converge. This presentation will demonstrate how 3D technology can be implemented at scale to ensure police accountability, strengthen criminal investigations, and promote human rights compliance — establishing new global standards for independent forensics in lethal police operations. 

Friday, February 19

7:15 am – 8:15 am

Presenters:
Colleen M. Fitzpatrick, PhD
Identifinders International LLC
Fountain Valley, CA

Danny Hellwig, MSFS 
Resolve Forensics
Salt Lake City, UT

Learning Objectives: Upon attending this presentation, attendees will gain an understanding of how the need to identify highly compromised human remains has prompted innovations in DNA analysis, bioinformatics, and Forensic Investigative Genetic Genealogy (FIGG), leading to identifications thought to be beyond the limits of modern technology.

Impact Statement: This presentation will impact the forensic science community by demonstrating how innovations in DNA analysis, bioinformatics, and FIGG are doing more and more with less and less, often with spectacular results.

Leonard Lake and Charles Ng were a serial killer duo operating in Central California between 1982 and 1985. The pair are credited with 11 confirmed and are suspected in as many as 25 additional homicides, although the true number of victims may never be known. While several of their victims were buried near Lake's cabin in Wilseyville, CA, many were cremated in a homemade kiln located on the property.

Lake committed suicide by ingesting cyanide four days after the pair were arrested in 1985. Ng escaped to Canada but was extradited to California in 1991. In 1999, Ng was convicted of 11 counts of first-degree murder and sentenced to death. Following California's 2019 moratorium on executions, Ng remains incarcerated at the California Medical Facility in Vacaville, CA.

In August 2021, the Calaveras County Sheriff's Office initiated an effort to use FIGG to identify as many of the unidentified Lake and Ng victims as possible. The effort has proven to be exceptionally challenging. Although the remains of several victims were found buried intact, the majority consist of highly fragmented skeletal material exhibiting extensive thermal damage. More than 1,000 fragments are present. 

The highly compromised nature of the remains, along with their small size and fragile condition, has pushed the limits of current forensic DNA technology. The two major challenges have been the high level of bacterial content and the limited human DNA diversity. Each would have been difficult on its own, but the combination of the two has been the core limitation, even when quantifiable DNA has been detected. Traditional assumptions based on visual inspection have not reliably predicted the presence of usable DNA; specimens that appeared severely compromised have produced meaningful amounts of human DNA, while others that appeared more promising have not. Despite these challenges, several new victims have been successfully identified, and at least one suspected victim has been confirmed.

This presentation describes our efforts over the past five years to apply specialized forensic DNA technologies to the identification of previously unknown Lake and Ng victims. We describe the technical challenges we have faced, how we have worked to overcome these challenges, and why more difficult specimens may still be pushed over the finish line through a collaborative development of methods beyond normal, traditional sequencing. The presentation will illustrate our success through a case study on the identification of Wilseyville Jane Doe, a young female victim who was identified based on only a single small bone fragment and a rare X-inheritance pattern.