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Cold Case Center

Case Studies

Professionally written examinations of solved or significantly advanced cold cases — investigative timelines, turning points, technologies used, and lessons learned.

Case studies rely on publicly available, properly attributed information. Confirmed facts are distinguished from analysis or investigative inference. Individuals are not identified as suspects unless that designation has been publicly confirmed by the investigating agency or documented in court records.

FeaturedResolved — ConvictedHomicide / Serial Offender

The Golden State Killer: Cold Case Resolution Through Investigative Genetic Genealogy

Multiple Counties, CaliforniaSacramento County Sheriff's Office; FBI; California DOJOriginal period: 1976–1986Resolved: 201818 min read

Case Overview

The Golden State Killer case represents one of the most significant cold case resolutions in American law enforcement history. Joseph James DeAngelo, a former police officer, was identified as the perpetrator of at least 13 murders, 50 rapes, and 100 burglaries committed across California between 1976 and 1986. The case had remained unsolved for more than three decades before investigators used investigative genetic genealogy to identify DeAngelo in 2018. He pleaded guilty in 2020 and was sentenced to life in prison without the possibility of parole.

Field Brief-Style Training Scenario

Your agency has a 1989 homicide with preserved biological evidence and no CODIS match. A new investigator assigned to the case proposes submitting the DNA profile to GEDmatch for investigative genetic genealogy analysis. What agency-level approvals are required? What documentation must be completed before submission? What investigative steps follow a genealogical candidate identification? What are the legal and ethical considerations?

Investigative Genetic Genealogy (GEDmatch)Advanced STR DNA ProfilingForensic Genealogy ResearchSurveillanceDiscarded DNA Collection

Complete Source List

Sacramento County Sheriff's Office — Golden State KillerDOJ — People v. DeAngelo Case InformationNIJ — Investigative Genetic Genealogy

McNamara, M. (2018). I'll Be Gone in the Dark. Harper.

Published:
FeaturedOngoing — Multiple IdentificationsUnidentified Remains

Unidentified Remains and NamUs: How Database Integration Resolves Decades-Old Cases

NationwideNational Missing and Unidentified Persons System (NamUs); Participating Medical Examiners and Law Enforcement AgenciesOriginal period: Various — 1970s to presentResolved: 202414 min read

Case Overview

Thousands of unidentified human remains cases remain open in the United States. The National Missing and Unidentified Persons System (NamUs) was established to address the fragmented, inconsistent approach to these cases by creating a centralized, searchable national repository. This case study examines how NamUs, in combination with investigative genetic genealogy and improved interagency data sharing, has enabled the identification of individuals whose remains had gone unidentified for decades.

Field Brief-Style Training Scenario

Your agency discovers unidentified skeletal remains during a construction project. The remains appear to be at least 15 years old. No missing persons report in your jurisdiction matches the biological profile. What steps should you take to enter the case in NamUs? What forensic services are available at no cost? Under what circumstances would you consider an IGG referral? Who are the appropriate agency contacts?

NamUs DatabaseCODIS DNA ComparisonInvestigative Genetic GenealogyForensic AnthropologyFacial ReconstructionIsotope Analysis

Complete Source List

NamUs — National Missing and Unidentified Persons SystemNIJ — Unidentified Human RemainsNIJ — NamUs Program Overview
Published:
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