Reference · Resource
Cold-Case Research Glossary
Plain-language definitions of the terms used in cold-case research — from chain of custody to statute of limitations.
By Second Trace editorial · Published August 30, 2026 · Updated August 30, 2026 · 6 min read
In short
A plain-language reference for the terms used in cold-case research — from 'allegation' and 'chain of custody' to 'statute of limitations' and 'ViCAP.' Definitions are descriptive and neutral; they are provided for clarity, not as legal advice.
Terms
Allegation
A claim that someone did something, asserted but not yet established by evidence.
Chain of custody
The documented sequence of who has held an item and when — the record that makes an item's handling auditable.
Circumstantial evidence
Evidence that implies a fact without directly proving it; it supports an inference rather than establishing the fact outright.
Cold case
An investigation that has become inactive — often for lack of new leads — and remains unresolved over an extended period.
Cold case review unit
A team, typically within an agency or organization, that re-examines inactive cases for new leads or new forensic opportunities.
Corroboration
Independent confirmation of a claim by a second source or item of evidence that does not depend on the first.
Direct evidence
Evidence that, if accepted, directly establishes a fact — such as a record, a document, or a first-hand account.
Disputed account
Two or more conflicting accounts of the same event, recorded side by side rather than merged into one version.
Exculpatory
Tending to clear a person of blame or involvement.
Fact (confirmed)
A claim that is sourced and corroborated by independent material and not contradicted by stronger evidence.
Hearsay
An out-of-court statement offered as evidence of the truth of what it asserts. Relevant to research context; admissibility is a separate legal question.
Hypothesis
A proposed explanation advanced to be tested against the evidence, with criteria that would show it to be wrong.
Inculpatory
Tending to implicate or point toward a person's involvement.
Inference
A conclusion drawn from evidence — reasoning, not observation — and therefore labeled as such.
Jurisdiction
The authority and geographic scope of a legal body to handle a matter.
Lead
A specific, actionable line of inquiry worth pursuing — a concrete next step, not a conclusion.
NamUs
The National Missing and Unidentified Persons System, a U.S. clearinghouse administered by the National Institute of Justice.
Open-source intelligence (OSINT)
Information gathered from publicly available, permitted sources — as opposed to restricted or access-controlled systems.
Presumption of innocence
The principle that a person is considered innocent until proven guilty through a lawful process.
Primary source
Original material closest to the event — a record, document, photograph, or first-hand account.
Provenance
The origin and history of an item: who produced it, when, and through what channel it reached the record.
Redaction
Removing or obscuring sensitive information before sharing or publishing an item.
Reliability assessment
A recorded judgment of how trustworthy a source is, attached to the item so later readers can weigh it.
Secondary source
Material that analyzes, summarizes, or reports on primary sources — such as a news article or a scholarly commentary.
Statute of limitations
The legal time limit within which charges or claims may be brought, which varies by offense and jurisdiction.
Testimony
An account given by a person — evidence, but not the same as a confirmed fact.
Timeline
A dated, sourced sequence of events, with each entry's certainty and source recorded.
ViCAP
The FBI's Violent Criminal Apprehension Program, a national database for analyzing violent crime patterns.
A note on this glossary
These definitions are written for researchers, journalists, and members of the public working with case information. They describe how terms are commonly used in research and documentation. Where a term has a specific legal meaning, that meaning is a question for a qualified professional — this glossary is not legal advice and does not interpret the law of any jurisdiction.
Put this into practice
Second Trace is a workspace for organizing case information with full provenance. These capabilities map directly to the method above:
Related resources
Timelines
Cold-case timeline →A step-by-step method for building an accurate cold-case timeline — separating exact, approximate, and disputed dates, and keeping every entry tied to its source.
Evidence
Organizing evidence →A practical framework for organizing evidence in large, long-running investigations — provenance, chain of custody, and how to keep thousands of items findable.
Method
Facts, allegations & theories →A working taxonomy for sorting confirmed facts, allegations, testimony, inference, and theory in a case record — and why the distinction must survive export.