Standardization of forming and expressing preliminary evaluative opinions on digital evidence
Elsevier (Forensic Science International: Digital Investigation) · 2020
Identifier: DOI 10.1016/j.fsidi.2019.200888
Access and status
Cost
Paywalled
Behind a subscription or per-item charge. Check whether your firm, university or public library already has access before paying at the door.
Status
Current
Current as at the verification date below. Standards and tools both move — confirm at source before you rely on it.
What it is
Eoghan Casey's paper in Forensic Science International: Digital Investigation on how digital forensic practitioners should form and state evaluative opinions, importing the strength-of-evidence reasoning used elsewhere in forensic science into digital evidence and proposing a standardised scale for preliminary opinions.
Who it is for, and when
This is the current-generation reference for the wording problem every testifying examiner has: how confidently may you state that these artefacts support a particular activity? It gives you a defensible, citable basis for graded language instead of ad hoc adjectives, and it gives counsel a yardstick for testing whether an opposing expert overstated. Read it alongside Casey's 2002 error and uncertainty paper to see how the argument matured.
What it does not cover
It addresses how to express an opinion, not how to reach it — no examination methodology and no artefact analysis. Elsevier paywall applies, and adoption of the proposed scale is not universal, so do not present it as a settled standard.
Go to the source
Open at doi.org (opens in a new tab)https://doi.org/10.1016/j.fsidi.2019.200888
Details
- Type
- Paper or report
- Written for
- AdvancedLawyers and courtsAdvanced, Lawyers and courts
- Publisher
- Elsevier (Forensic Science International: Digital Investigation)
- Year
- 2020
- Identifier
- DOI 10.1016/j.fsidi.2019.200888
- Topics
- expert-testimony, error-rates, standards-development, legal-admissibility
- Checked at source
Related entries
Eoghan Casey's paper in IJDE 2002, Volume 1, Issue 2, which took apart the then-common claim that digital evidence is exact and argued that error, uncertainty and data loss are intrinsic to it and must be stated. It proposed expressing a level of certainty in conclusions rather than asserting them flatly.
A book for technologists who are about to testify: how the gatekeeping standards work, how to establish and defend qualifications, how to present technical material to a lay fact-finder, and where technical witnesses habitually lose credibility.
The decision holding that the Federal Rules of Evidence, not Frye's general-acceptance test, govern expert scientific testimony, and that the trial judge acts as a gatekeeper for reliability and fit. It offers a non-exclusive list of considerations: testability, peer review and publication, known or potential error rate, standards controlling the technique's operation, and general acceptance.
A single-author treatment of digital evidence that puts investigative reasoning and admissibility ahead of tooling, then works through Windows, Unix, Macintosh, mobile and network evidence sources. Roughly half the book is about how to reason from evidence to a defensible conclusion and how that conclusion survives a courtroom.
An 81-page NIJ guide on the legal handling of digital evidence: search and seizure issues including the Fourth Amendment, the Electronic Communications Privacy Act and the Privacy Protection Act; maintaining evidence integrity; pretrial preparation including authentication and hearsay; courtroom presentation and expert testimony; and a chapter on child pornography cases. Appendices include consent forms and evidence return stipulations.