FBINAA Associate Q1 Magazine

F B I N A A . O R G | Q 1 2 0 2 2

BEST PRACTICES FOR EXCULPATORY DIGITAL EVIDENCE

SY RAY

Over the last 25 years, I have investigated, peer-reviewed, and consulted on thousands of criminal investigations in which mobile device records were obtained for their evidentiary value, providing the driving force in securing convictions. Conversely, I have seen the records exonerate an individual who was thought to have committed the crime, but ultimately did not. By utilizing evidence-based policing, we can develop best practices when analyzing mobile device records while ensuring exculpatory evidence is preserved and identified. The evidence-based policing (EBP) concept of encouraging law enforcement agencies to adopt problem-solving philosophies based on the best available evidence to create policies and procedures ensures effective and unbiased investigative processes. Mobile Device Records – Third party records maintained in the normal course of business by telecommunication providers and obtained by law enforcement in reference to a criminal investiga - tion by a probable cause-based search warrant. Mobile Device Records provide incredible insight on trends and anomalies related to who someone communicates with, the frequency of that communication, travel patterns, Evidence-Based Policing – “The use of the best available re - search on the outcomes of police work to implement guidelines and evaluate agencies, units and officers.” 1

detailed location information, and periods of no activity that, when combined, provide a detailed pattern of that person’s life. Exculpatory Evidence – “Evidence that tends to clear an indi - vidual from alleged fault or guilt.” 2 This type of evidence is evidence that would indicate a particular person did not commit a crime or was not in the area where the crime was committed. All criminal justice practitioners can support the philosophy that law enforcement should make every effort to identify and preserve exculpatory evidence when it is known it does or may exist. ESTABLISHING EVIDENCE-BASED POLICING BEST PRACTICES Establishing Evidence-Based Policing Best Practices Can we apply the evidence-based policing philosophy to the exculpatory nature of mobile device records to establish a best practice? The simple answer is yes, but the moral answer driven by ethical investigative practices requires it. The first step to instituting such a practice will require a clear explanation of why mobile device records provide empiri - cal exculpatory evidence. All of this is related to pattern of life. Pattern of life is the ability to analyze sufficient data to visualize routines. Routines can include call, text, and data patterns that identify a particular individual’s behavior and interactions that are unique to the individual. Routines can include location data that identifies travel and stationary patterns that are unique to a particular individual’s behavior. A detailed routine can establish the identity to the mobile device user. If users change, the be- havior pattern associated with the device changes. It is a digital fingerprint. Mobile device records are extremely powerful evidence, but only evidence of device usage, not necessarily who was using the device. It is the process of analyzing and developing distinct patterns of life that can be associated to a unique individual that provides the “who.” Without this analysis, we are only left with the “what.” To associate a particular user to a specific device, we must analyze and develop a unique pattern of life that can be associated to the user. The pattern of life will always exist and,

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