Digital Forensic Evidence in the Courtroom: Understanding Content and Quality

TLDR: The Daubert standard provides judges with an objective set of guidelines for accepting scientific evidence, and is the key to establishing a timeline and correlating important events in cases where information is hidden, erased, or otherwise altered.

Abstract: ¶1 With the widespread permeation of continually advancing technologies into our daily lives, it is inevitable that the product of those technologies, i.e. digital information, makes its way into the courtroom. This has largely occurred in the form of electronic discovery, or "e-discovery," where each party involved in an action provides the relevant information they possess electronically. However, in cases where information is hidden, erased, or otherwise altered, digital forensic analysis is necessary to draw further conclusions about the available evidence.1 Digital forensic analysis is analogous to more traditional forensic analysis. For example, in criminal cases where a firearm was used in the commission of the crime, but the gun is not readily admissible,2 forensic science is necessary to trace the origin of the weapon, perform fingerprint analysis on it, and compare fired bullet casings to ensure the weapon used and the weapon analyzed are one and the same.3¶2 In sum, digital forensics is the preservation and analysis of electronic data.4 These data include the primary substantive data (the gun) and the secondary data attached to the primary data, such as data trails and time/date stamps (the fingerprints).5 These data trails and other metadata markers are often the key to establishing a timeline and correlating important events.6I. A BRIEF HISTORY OF DIGITAL FORENSICS¶3 A forensic report, whether for digital evidence or physical evidence, must have conclusions that are reproducible by independent third parties.7 So, facts discovered and opinions formed need to be documented and referenced to their sources. Why? Ones and zeros do not lie. Therefore, forensic reports that contain opinions based upon properly documented digital sources are much more likely to withstand judicial scrutiny than are opinions based on less reliable sources.8¶4 The reigning case in scientific evidence admission is Daubert v. Merrell Dow Pharmaceuticals Inc.9 The decision in Daubert set forth a five-pronged standard for judges to determine whether scientific evidence is admissible in federal court. The Daubert standard applies to any scientific procedure used to prepare or uncover evidence and comprises the following factors:(1) Testing: Has the scientific procedure been independently tested?(2) Peer Review: Has the scientific procedure been published and subjected to peer review?(3) Error rate: Is there a known error rate, or potential to know the error rate, associated with the use of the scientific procedure?(4) Standards: Are there standards and protocols for the execution of the methodology of the scientific procedure?10(5) Acceptance: Is the scientific procedure generally accepted by the relevant scientific community?¶5 The Daubert standard provides judges with an objective set of guidelines for accepting scientific evidence. Following Daubert, the decision in Kumho Tire v. Carmichael11 extended the Daubert standard to the qualification of expert witnesses by its interpretation of Federal Rule of Evidence ("FRE") 702. FRE 702 provides guidelines for qualifying expert witnesses, stating that the expert can have "scientific, technical, or other specialized knowledge." The Kumho Tire court extended the Daubert standard to apply to experts with technical or specialized knowledge, and not simply those called to testify regarding their scientific knowledge.¶6 The majority of jurisdictions in the country favor the Daubert standard over the "general accepted practices" standard set forth in Frye v. United States, 293 F. 1013 (1923).12 For jurisdictions in which Daubert is followed, there are a number of practical points that both attorneys and judges will benefit from knowing in order to understand and effectuate the guidelines set forth in the Daubert standard. This article's goal is to elucidate those practical high-level points, thereby allowing counsel or judge to review technical expert reports and spot potential weaknesses. …