Digital Evidence
Digital forensics encompasses the activity of computers, networks, databases, cell phones, cell towers, digital cameras, GPS devices and other types of digital or electronic evidence. Issues to be considered may include search and seizure, preservation of data, privacy, acquisition, analysis of digital media, and the production of a report that can be used in court.
National Academy of Sciences Report - See pp. 179-182 for the National Research Counsel's evaluation of Digital and Multimedia Analysis.
Scientific Working Group on Digital Evidence - composed of member organizations that are actively engaged in the field of digital and multimedia evidence. Works to foster communication and cooperation and ensure quality and consistency within the forensic community.
Forensic Examination of Digital Evidence: A Guide for Law Enforcement, Electronic Crime Scene Investigation: An On-the-Scene Reference for First Responders, and Digital Evidence in the Courtroom: A Guide for Law Enforcement and Prosecutors - these guides set out the National Institute of Justice's recommendations for how law enforcement and crime scene investigators should handle digital evidence. Evidence on cell phones or computers can be changed or destroyed if proper techniques are not used to forensically analyze the data. This guide may be used to cross examine law enforcement officers who did not follow the recommendations for handling this type of evidence.
NIST has published Guidelines on Mobile Device Forensics that establishes methods for preserving and processing digital information on mobile devices.
Digital Evidence by Jeff Welty, 2015. A guide to the legal issues presented by the collection of digital evidence in criminal cases, written mainly for North Carolina judges, lawyers, and officers. This book addresses how such evidence may be obtained and the rules that govern its use in court and is available for purchase.
Online Resources
- NACDL's Fourth Amendment Center provides resources to criminal defense lawyers and their clients through a toolkit of resources for lawyers and litigation suppport as well as continuing education on emerging issues regarding technology, privacy, and constitutional rights.
- Digital Forensics for Attorneys - a 60 minute on-demand School of Government virtual CLE by digital forensics expert Larry Daniel that provides an overview of digital forensic concepts, case examples, and relevant terminology. Attorneys will learn the basic information needed to understand the process of computer and cell phone forensics and the proper methods for search and seizure of electronic evidence. The presentation can be viewed for free or for CLE credit.
- Getting Facebook into Evidence - this guide, prepared by Larry Daniel, provides information on the collection, preservation, and authentication of Facebook evidence from a digital forensics perspective.
- Guide to Child Pornography Cases - Larry Daniel addresses common issues with child pornography cases in this guide. Topics include what information an expert will need and what services an expert may be able to provide. Daniel provides an explanation of technical terms commonly used in these cases.
- Overcoming Hurdles in Digital Evidence - Attorney Howard Kurtz has posted information on his blog about how to view video evidence. This information may be useful for attorneys seeking to open videos from surveillance cameras, police departments, or other video evidence that is provided in a seemingly corrupt digital .avi format.
- The Fourth Amendment in the Digital Age - this one-day NACDL symposium was recorded on April 3, 2015 and is available for viewing. Topics include how digital searches, government surveillance programs and new technologies are impacting Fourth Amendment protections in criminal cases.
- Subpoena Guide - this guide contains addresses and phone/fax numbers for the legal departments/subpoena compliance centers of cellular providers and social media sites. Please be aware of 2014 Formal Ethics Opinion 7 when issuing subpoenas. John Rubin's 2017 blog post on subpoenaing-of-state materials is available here. Email Sarah Rackley Olson if you have any corrections or updated information for the subpoena guide.
- Online Directory - search this directory of wireless and internet service providers to find contact information for legal departments. This directory was created for law enforcement use through a grant from the DOJ.
- Retention Periods of Major Cellular Service Providers - The Computer Crime and Intellectual Property Section of the U.S. Department of Justice gathered information about the retention periods for call details, cell tower information, text message content, pictures, and other types of data. This information has been posted online by the ACLU.
- FoneFinder - this website gives the name of the service provider associated with a phone number.
- Social Media Law Enforcement Guides - the Electronic Frontier Foundation received a number of guides regarding information that is maintained by various social networking sites and how to request that information. The guides are posted on their website, under the "documents" tab, scroll down to Social Media Law Enforcement Guides.
- UNC School of Government posts on digital evidence:
- Search Warrants Authorizing Law Enforcement Computer Hacking and Malware - July 23, 2018 blog post by Jeff Welty.
- Supreme Court Rules that Obtaining Cell Site Location Information Is a Search - June 25, 2018 blog post by Jeff Welty.
- Obtaining and Admitting Evidence from a Vehicle’s Black Box - Feb. 14, 2018 blog post by Shea Denning.
- When a Person Commits a Crime, Is There Probable Cause to Search the Person’s Phone for Evidence? - Jan. 30, 2018 blog post by Jeff Welty.
- Real-Time Cell Phone Tracking Update, Including a New Case - Jan. 29, 2018 blog post by Jeff Welty.
- Discovery of Officers’ Text Messages - Jan. 8, 2018 blog post by Jeff Welty.
- Questions and Resources about Searches of Cloud Storage - Dec. 13, 2017 blog post by Jeff Welty.
- New Cases Hold that Using a Stingray Is a Search - Oct. 16, 2017 blog post by Jeff Welty.
- State v. Thompson Tells a Tale of Two Facebook Screenshots - Oct. 11, 2017 blog post by Shea Denning.
- U.S. Supreme Court Preview: Carpenter v. United States - Sept. 25, 2017 blog post by Jessie Smith.
- Serial, Cell Site Location Information, and Experts . . . on a Wednesday - Sept. 20, 2017 blog post by Shea Denning.
- Facial Recognition, Biometric Identification, and the Fifth Amendment - Sept. 18, 2017 blog post by Jeff Welty.
- Update on Fingerprints, Phones, and the Fifth Amendment - Jan. 23, 2017 blog post by Jeff Welty.
- Persistent Aerial Surveillance and the Fourth Amendment - Dec. 12, 2016 blog post by Jeff Welty.
- Caught on Camera - Oct. 5, 2016 blog post by Shea Denning.
- Probable Cause and Search Warrants for Cell Phones - Oct. 3, 2016 blog post by Jeff Welty.
- Pole Camera Surveillance Under the Fourth Amendment - July 12, 2016 post by Bob Farb.
- One Case, Two Ways of Authenticating Video - June 27, 2016 post by Jeff Welty.
- Fourth Circuit Reverses Graham: No Warrant Required for Historical Cell Site Location Information - June 6, 2016 post by Jeff Welty.
- State Supreme Court Reverses Court of Appeals Regarding Authentication of Surveillance Video - Apr. 18, 2016 post by Jeff Welty.
- Court of Appeals Upholds Admissibility of Social Media Evidence Based on Circumstantial Evidence of Authenticity - Mar. 7, 2016 post by Jeff Welty.
- State v. Perry, Cell Site Location Information, and the Exclusionary Rule - Sept. 21, 2015 post by Jeff Welty.
- Can a Magistrate Issue a Search Warrant for a Computer or a Cell Phone? - Sept. 1, 2015 post by Jeff Welty.
- Advice to Officers After Graham - Aug. 25, 2015 post by Jeff Welty about how United States v. Graham applies in NC.
- Fourth Circuit: Cell Site Location Information Requires a Search Warrant - Aug. 10, 2015 post by Jeff Welty about United States v. Graham, a 4th Circuit opinion holding that obtaining cell site location information through a court order under 18 U.S.C. § 2703(d) constituted an unreasonable warrantless search.
- Important New Opinion on Cell Phone Tracking - May 7, 2015 post by Jeff Welty about an 11th Circuit opinion holding that law enforcement may obtain historical cell site location information without a search warrant, using a court order based on less than probable cause.
- Recent Case on Authentication of Surveillance Video - Feb. 19, 2015 post by Jeff Welty
- Authenticating Social Media Evidence - Dec. 2, 2014 post by Jessica Smith
- Search Warrants for Digital Devices - this 2014 article by Jeff Welty discusses requirements for search warrants for digital devices. The intended audience is law enforcement offices, but the article contains footnotes with citations to legal authority.
- Stingrays - Oct. 22, 2014 post by Jeff Welty on IMSI catchers that simulate cell towers and connect with cell phones nearby.
- Computer Searches and Plain View - Nov. 21, 2013 post by Jeff Welty
- Returns and Inventories for Computer Search Warrants - Nov. 19, 2013 post by Jeff Welty, provides information on requirements for returns and inventories for computer search warrants.
- Testimony about Tracking - Oct. 22, 2013 post by Jeff Welty, provides an overview of case law on testimony regarding GPS tracking and cell tower tracking.
- Shea Denning's October 2012 North Carolina Criminal Law blog post, State v. Wilkerson and the Authentication of Electronic Evidence, provides an overview of North Carolina case law on the authentication of text messages.
- Digital Forensics for Legal Professionals: Understanding Digital Evidence From The Warrant To The Courtroom, published Sept. 2011 by Larry and Lars Daniel is available for purchase.
- Computer Forensics for Dummies by Linda Volonino and Reynaldo Anzaldua - this book provides an excellent introduction to the topic. An overview of the materials is available in an online "cheat sheet."
- Association of Digital Forensics, Security and Law - The ADFSL is a non-profit organization that supports the Journal of Digital Forensics, Security and Law, the Conference on Digital Forensics, Security and Law, and a listserve in support of the journal, the conference and other issues relating to digital forensics, security and law.
Digital Evidence Experts
For information about experts who have previously worked on cases involving digital evidence, see this online database.
Articles
- Recent news articles - this page contains links to recent press coverage of local and national cases involving digital evidence and is updated regularly.
- Prosecutors’ use of mobile phone tracking is ‘junk science,’ critics say - this article in the June 2013 ABA Journal describes a case where a U.S. District Court judge excluded cell tower evidence, finding that the government had not demonstrated that testimony on the subject was reliable.
- The Limitations and Admissibility of Using Historical Cellular Site Data to Track the Location of a Cellular Phone by Aaron Blank, XVIII RICH. J.L. & TECH. 3 (2011). Discusses how a cellular network works, how a cell phone tracks its location, limitations on cell site data as a tracking method, admissibility of cell site data, and constitutional implications for seizure of cell site data. Provides practical suggestions concerning admission and exclusion of this evidence.
From the University of North Carolina School of Government's Criminal Law Blog:
- Georgia Case on Searching Cell Phones Incident to Arrest - Analysis of a recent decision by the Georgia Court of Appeals (Hawkins v. State) regarding searches of cell phone data incident to arrest.
- Authentication and Hearsay Issues with Phone Records - This post considers whether hearsay and authentication objections can be overcome where the state seeks to introduce a defendant's phone records using an affidavit stating the phone records are business records.
- Discovery in Child Pornography Cases - Discussion of the discovery process in child pornography cases and whether a copy of the defendant's hard drive may be provided so that a defense expert can analyze it.
- Sexting - Inquires about the possibilities of criminal prosecution for sexting (sending pornographic digital images via text message) by minors.
- Computer Searches and the Scope of Consent - Suggests a possible application of traditional notions of scope of consent in computer searches by law enforcement.
- Encrypted Computer Files and the Fifth Amendment - Discusses the legal and technical challenges of accessing encrypted files on a suspect's computer, including consideration of the Fifth Amendment right against self-incrimination.
- Warrantless Searches of Computers and Other Electronic Devices - Includes a link to a list of list of cases on subjects such as cell phones searches incident to arrest, whether a consensual search of a residence includes the computers there, and privacy expectations in laptop issued by an employer.
- The Second Look Doctrine, Part I and Part II - This two-part post covers the "second look" doctrine, which holds that if the police looked at, or could have looked at an item, such as a cell phone, during the arrest and booking process and are still in possession of the item, they can take a second look at it later, without a warrant, without violating the Fourth Amendment. The first post explains the doctrine; the second addresses some issues of applying it, including whether there is a probable cause requirement.
- Searching Cell Phones for Evidence of Texting While Driving - Examines the investigative authority of officers attempting to enforce laws against texting while driving.
Forensic Magazine regularly posts articles on digital forensics on its Digital Forensic Insider page. Recent topics include: SIM card forensics, cell phone evidence, and collecting computer evidence.
From the Electronic Frontier Foundation:
- Cell Tracking - Considers whether the government can use cell phone records to track the physical location of a suspect without first obtaining a warrant based on probable cause.
- Printers - Discusses the practice of color laser printer manufacturers encoding of identifying information on each page printed by the machine. Explores the privacy implications of this practice.
- Revised Opinion in Privacy Case Blurs Clear Limits to Digital Search and Seizure - Discusses a 2010 Ninth Circuit case dealing with proper procedure for electronic searches.