40 Pages Posted: 28 Sep 2004 Last revised: 13 Jul 2015
This essay shows how existing rules of criminal procedure are poorly equipped to regulate the collection of digital evidence. It predicts that new rules of criminal procedure will evolve to regulate digital evidence investigations, and offers preliminary thoughts on what those rules should look like and what institutions should generate them.
Digital evidence will trigger new rules of criminal procedure because computer-related crimes feature new facts that will demand new law. The law of criminal procedure has evolved to regulate the mechanisms common to the investigation of physical crime, namely the collection of physical evidence and eyewitness testimony. Existing law is naturally tailored to the law enforcement needs and privacy threats they raise. Computers have recently introduced a new form of evidence: digital evidence, consisting of zeros and ones of electricity. Digital evidence is collected in different ways than eyewitness testimony or physical evidence. The new ways of collecting evidence are so different that the rules developed for the old investigations often no longer make sense for the new. Rules that balance privacy and public safety when applied to the facts of physical crime investigations often lead to astonishing results when applied to the facts of computer crime investigations. They permit extraordinarily invasive government powers to go unregulated in some contexts, and yet allow phantom privacy threats to shut down legitimate investigations in others.
This Essay explores the dynamics of computer crime investigations and the new methods of collecting electronic evidence. It contends that the new dynamics demonstrate the need for procedural doctrines designed specifically to regulate digital evidence collection. The rules should impose some new restrictions on police conduct and repeal other limits with an eye to the new social and technological practices that are common to how we use and misuse computers. Further, the Essay suggests that we should look beyond the judiciary and the Fourth Amendment for the source of these new rules. While some changes can and likely will come from the courts, many more can come from legislatures and executive agencies that can offer new and creative approaches not tied directly to our constitutional traditions.
Indeed, a number of new rules are beginning to emerge from Congress and the Courts already. In the last five years, a number of courts have started to interpret the Fourth Amendment differently in computer crime cases. They have quietly rejected traditional rules and created new ones to respond to new facts of how computers operate. At a legislative level, Congress has enacted computer-specific statutes to address other new threats to privacy. The changes are modest ones so far. Taken together, however, the new constitutional and statutory rules may be seen as the beginning of a new subfield of criminal procedure that regulates the collection of digital evidence.
This Essay will proceed in three parts. Part One compares the basic mechanisms of traditional crimes and computer-related crimes. It explains how the switch from physical to electronic crimes brings a switch from physical evidence and eyewitness testimony to digital evidence, and how investigators tends to use very different methods of collecting the two types of evidence. Part Two turns from the facts to the governing law, focusing on the Fourth Amendment's prohibition on unreasonable searches and seizures. It shows that existing Fourth Amendment doctrine is naturally tailored to the facts of physical crimes, but that a number of difficulties arise when that doctrine is applied to the facts of computer crime investigations. Part Three argues that new rules are needed to govern digital evidence collection, and offers preliminary thoughts on what those rules might look like and what institutions should generate them. It also shows that courts and Congress already have begun responding to the problem of digital evidence with a number of computer-specific rules.
Keywords: Fourth Amendment, computers, digital evidence
JEL Classification: K14
Suggested Citation: Suggested Citation
Kerr, Orin S., Digital Evidence and the New Criminal Procedure. 105 Columbia Law Review 279 (2005); GWU Law School Public Law Research Paper No. 108. Available at SSRN: https://ssrn.com/abstract=594101