The Evolution of Blood-Stain Pattern Analysis Verdicts in the Courtroom

Blood-stain pattern analysts are often called upon to help determine events surrounding a crime, and today their testimony is accepted in courts across the country. A recent New York Times Magazine article provides a window into the history of blood-stain pattern analysis and a closer look at how the discipline took hold in the American justice system.

Looking back to 1954, we can see that modern bloodstain-pattern analysis began with a small group of scientists and forensic investigators testifying as experts in a new technique. As the years progress, this group begins to train many more police officers, investigators and crime-lab technicians, who go on to testify in court as well.

However, in recent years, the training of these experts and the validity of the field itself have been called into question by various scientists and legal scholars.

Defendants began to appeal the legitimacy of the experts’ testimony, and their cases started to make their way to state appeals courts. Over time, the New York Times articles shows that once one court ruled that bloodstain testimony was admissible, others often followed suit, basing the decision on predecessor’s rulings. The timeline shows that judges have relied more on their own or the testifying experts’ assessment when examining the reliability and accuracy of blood stain pattern analysis, not objective proof.

The article highlights the groundbreaking 2009 National Academy of Sciences study that found major deficiencies in the United States forensic science field. The reports states, “The uncertainties of bloodstain-pattern analysis are enormous,” and highlights that analysts’ opinions are more subjective than scientific.

The Center for Statistics and Applications in Forensic Evidence was created in response to the 2009 NAS report, with a mission of building a stronger scientific foundation for the analysis and interpretation of forensic evidence. Our experts are studying a variety of forms of pattern and digital evidence, to include blood-stain analysis, and are working to develop new tools to improve accuracy.  Learn how CSAFE is using statistical modeling software to gain a better understanding of how blood behaves, and more about a new blood spatter database designed to test analysis methods in our news section.

Human Versus Machine: NIST Study Investigates AI’s Role in Forensic Face Recognition

facial recognition

The debate of human versus machine continues to increase with rapidly changing technology. A new study by the National Institute of Standards and Technology confronts this conflict head-on with an investigation of accuracy in forensic face examination.

A photo from a security camera can play a critical role in criminal cases, determining the fate of the suspect. Trained forensic face examiners provide courtroom testimony, informing a jury whether that still image actually represents the accused.

NIST researchers and three university partners have combined the disciplines of forensic science, psychology and computer vision to determine just how good facial recognition experts really are. For the first time, researchers reveal the science behind the work of forensic face examiners, and raise the question of artificial intelligence’s role.

Researchers at NIST and organizations like CSAFE have revealed that algorithm performance has steadily increased over the past few years, and has valuable applications to forensic investigations. When comparing algorithms to human experts, the NIST study showed the highest accuracy in facial recognition was achieved with a collaboration of both the strengths of a human and a machine.

As a NIST Center of Excellence, CSAFE uses similar algorithmic approaches in other forensic disciplines to develop new tools to come alongside the human experts. Explore how our team is working to improve evidence analysis accuracy using algorithms in the comparison of cartridge cases and bullets.



An Inside Look into the Role of a Digital Evidence Expert

Men looking at computers

In a new weekly series launched by TODAY, reporters investigate the future of work in today’s ever-changing society. Technological advancements are fueling the creation of new jobs that may not have even existed a few years ago, but are set to proliferate within the next decade.

A fourth installment in this series gives readers an inside look into the role of one type of digital forensic specialist. As digital crimes continue to increase from year-to-year, and the majority of information worldwide moves to a digital format, the article highlights an expected increased demand for this specialty.

Digital forensics experts contribute to criminal investigations in multiple ways. The TODAY article highlights one example, experts who are responsible for catching criminals behind cyber-attacks and security breaches. Authorities rely on these specialists to identify and preserve digital evidence, and piece together the events surrounding a crime.

In the article, experienced digital forensic experts highlight real cases, emphasizing that no two crimes are alike. The experts stress the importance of approaching each case with unique and creative problem solving.

“The role calls for very specific skills, including understanding an attacker’s perspective, deep technical skills especially in how systems work with one another, and sharp and analytical mind,” says one digital forensics specialist.

Dig deeper into the responsibilities of a digital forensic expert focused on cyber-security in the TODAY article, and learn how CSAFE researchers are investigating other applications of digital forensics such as steganography and user-generated event data on our website.


Understanding How Statistics Can Address Forensic Science Challenges

This post is based on the article “Statistical Issues in Forensic Science” by CSAFE Co-Director Hal Stern of UCI. The full article was published in March 2017.

The way that forensic evidence and other expert testimony is presented in court is determined by legal precedent, especially the 1993 U.S. Supreme Court decision in Daubert v Merrell Dow Pharmaceuticals, and Rule 702 of the Federal Rules of Evidence.  These sources identify the trial judge as the “gatekeeper” to identify which testimony to allow, and set the expectation that such testimony “is based on sufficient facts or data” and “is the product of reliable principles and methods”. A 2009 National Research Council (NRC) report and a 2016 report of the President’s Council of Advisors on Science and Technology (PCAST) question whether a number of forensic science disciplines satisfy these expectations. Each calls for additional research to support the science underlying the analysis of forensic evidence.

A multidisciplinary approach is required to carry out such research because each discipline requires technical expertise to collect and prepare evidence and additional expertise to analyze and interpret the resulting data. Statistics has a crucial role to play in helping to address the challenges of forensic science.  Examples of the way that statisticians and the field of statistics can contribute are described below.

Reliability and validity

Perhaps the most important challenge facing forensic science after the 2009 NRC and 2016 PCAST reports is the need for data that assesses the reliability and validity of forensic examinations and conclusions.  Reliability refers to whether forensic measurements or judgements would be obtained consistently.  This includes considerations of repeatability, in which one asks if the same forensic examiner would draw the same conclusion if presented with the same evidence at a different time, and considerations of reproducibility, in which one asks if the same conclusion or measurement would be obtained by other examiners. Reliability is an important first consideration but even if forensic examinations in a particular domain are reliable, that does not indicate whether they are valid or accurate.  If a fingerprint examiner concludes that a latent print at the crime scene comes from the same source as a test impression made by the suspect (this conclusion is sometimes known as an identification), we need to know how accurate that conclusion is to make an informed judgment about the weight of evidence. The PCAST report carefully discussed what should be expected in validation studies (e.g., the true status of the samples should be known, the samples should be representative of casework, etc.).

PCAST indicated that statistical methods are well developed and have been validated for single source DNA evidence (or simple mixtures) and for latent print analysis, but reported that additional studies are needed regarding the validity of forensic examinations  in other forensic science disciplines. Assessing the reliability and validity of forensic examinations is a key step in developing sound science to measure the strength of evidence and statisticians can contribute to the design and analysis of such studies.

Task-relevant information and cognitive biases

Scientists are humans, not robots. As such, the field of forensic science, as any other domain involving human judgements, has the potential to be compromised by cognitivebias and other cognitive factors which can influence how data is collected, analyzed and findings are communicated. Cognitive bias is a term meant that refers to disconnects between observed behavior, and what would be considered by most as rational decision making.

There are a number of well-known cognitive biases that have been identified in other areas of human decision-making.  One example is known as confirmation bias, where examiners may tend to favor interpretations that confirm their own preconceptions about a suspect or the evidence. Another example are framing effects, where a forensic examiner may evaluate evidence differently depending on what  contextual information about the suspect or the crime scene was provided.

Statisticians can play a role in teams that study cognitive bias and in teams that try to determine what information should be deemed relevant for a particular task.

Causal inference

Forensic examiners working in crime scene investigation, arson and blood spatter analysis attempt to reconstruct the events leading up to a crime based on evidence found at the crime scene. This process is an effort to infer the causes of observed effects. These examiners face a challenging task because it is difficult to carry out realistic controlled experiments that would allow one to reliably distinguish between competing explanations. For example, the problem of determining if a fire developed naturally or by the use of an accelerant.

Statistical collaboration with practitioners in relevant disciplines will be valuable in strengthening inferences in these settings.

Case processing and procedures

Any process can benefit from careful analysis to understand potential limitations, bottlenecks or sources of error, and the forensic evidence analysis process is no exception.

Crime laboratories are often faced with an overwhelming workload, leading to backlogs that can slow the treatment of evidence. At the same time, maintaining quality forensic examinations  requires a quality assurance program that incorporates reanalysis of evidence or verification of conclusions.

Statistical methods can play a role in designing quality assurance programs that can improve efficiency of lab operations while simultaneously insuring the accuracy of conclusions.

Testifying on forensic evidence

Appropriate ways for presenting forensic evidence analysis in the courtroom is an important area of research. Several studies demonstrate the difficulty that jurors can have in understanding statistical ideas like the likelihood ratio and Bayes factor. The forensic science research community is still examining the best way to presnt such evidence in the courtroom.

Statisticians have an important role to play in developing approaches to presenting quantitative evaluations of evidence and in the design and analysis of juror studies to assess the effectiveness of alternative approaches.

How CSAFE Research is Advancing the Field of Forensics

Statisticians at the Center for Statistics and Applications in Forensic Evidence (CSAFE) work in partnership with NIST researchers, forensic science practitioners and scientists in a variety of disciplines to address the issues raised in the NRC and PCAST reports.

Our team is contributing to strengthening the statistical foundations of pattern and digital evidence through the study of existing methods and the development of new statistical to analyze and interpret data and evidence. Our goal is to help forensic scientists in their pursuit of reliable and accurate analyses of forensic evidence.

Learn more about our research.

This post is based on the article “Statistical Issues in Forensic Science” by CSAFE Co-Director Hal Stern of UCI. The full article was published in March 2017.

The Flipped Classroom: Strategies to Increase Student Engagement in Forensic Statistics

How often have you sat in a classroom, half-listening to a teacher lecture, feeling uninterested and not engaged? Many of us can relate to this type of often boring, idle instruction.

While some students may find long lectures on forensic statistics dry, a flipped-classroom approach can make statistics and its real-world applications to criminal investigations exciting and fun for all students. Try using this method to transform students from simply receptors of information to active participants in their learning.

Understanding the Flipped Classroom

Focusing on collaborative learning rooted in higher student-control, the flipped classroom reverses the traditional model of teaching to focus class-time not on lectures, but on problem-solving, projects and discussions.

Dr. Simon Cole, CSAFE researcher and professor at the University of California, Irvine is a strong believer in the flipped classroom, using it to teach his undergraduate course “Forensic Science, Law and Society.” He explains the theory behind its success.

“The flipped classroom is the idea that currently we use the classroom for content delivery such as lecturing or video and expect the students to solve problems at home through homework, writing exercises or tests. The flipped classroom says that’s exactly wrong,” said Cole.  “The thing about lectures is that it’s so passive. Students aren’t required to do anything. Lecturing is not the best way for students to learn, they need to be active with group exercises and solving problems.”

The flipped classroom first exposes students to new material outside of class through reading or lecture videos. Class time then becomes an opportunity for students to process what they’ve learned through time for inquiry and application with immediate feedback from peers and the instructor.

Advantages to Flipped Classroom Learning

  1. Promotes deeper learning through in-class opportunities that emphasize higher-level cognitive functions
  2. Gives students more control through freedom to learn at their own pace at home
  3. Increases student-centered learning and collaboration where students teach and learn concepts from each other with instructor guidance
  4. Enables instructors to better assess student understanding and adjust teaching methods accordingly

General Strategies to Implement

Cole paints a picture of the traditional classroom. “You have a huge room of students where 10 percent sit in the front and are working hard, 20 percent are in the back shopping on their computers, and many in the middle who are kind of confused and having trouble keeping up with the ones in the front,” he said. Cole recognizes that as a lecturer it’s hard to keep yourself from teaching only to the students in the front.  But the flipped classroom changes that.

Cole recommends that instructors move about the room, asking a variety of students questions. He suggests potentially cold calling on students and staying with them until they answer the question.

“I force myself to not let all the students in the front answer the questions and I learned much more about what the students were comprehending,” Cole said. “What I learned was that there were things that I had taught and lectured about for 10 minutes and it took them 2 or 3 weeks to understand that concept so I slowed down and didn’t move on until I called on someone at random, and they could explain it back to me.”

Another suggestion is to shorten lectures.  “All the studies say that no one can listen for more than 12 minutes, not even professors,” Cole said. He advises chunking his lectures into mini-lectures via podcast, allowing students more time to digest the material.

Specific applications of the Flipped Classroom to Forensic Statistics

“The flipped classroom works well with teaching forensic statistics because you can focus on statistical problems and slowly work through them together,” Cole said. “I have some very simple exercises with likelihood ratios such as “state the probability that you think it’s going to rain tomorrow and state how much you hate getting wet. Now show that you can plug those numbers into this equation and that will tell you you’re likelihood ratio and your utility function.” Through this hands-on approach, students are actively interacting with key statistical concepts, promoting a deeper understanding of its importance to criminal investigations.

CSAFE is committed to mentoring the next generation of forensic scientists, researchers, law enforcement agents, lawyers, judges and more. Our innovative approaches to enhancing education for students across the country are paving the way for new talent committed to the fair administration of justice.

The CSAFE undergraduate course “Forensic Science, Statistics and Law” will be taught again in Fall 2018. Cole is looking forward to utilizing the new UCI Anteater Learning Pavilion, featuring seating designed to facilitate flipped classroom collaborative work.

Learn more in the CSAFE news section, and explore additional undergraduate opportunities in our education center. For questions on how you can implement these techniques in your classroom, please don’t hesitate to contact us.


Statistical and Computational Tools for Automated Matching of Footwear Class Characteristics

This CSAFE Center Wide webinar was presented on April 27, 2018 by Dr. Charless Fowlkes, CSAFE researcher and associate professor of computer science at University of California, Irvine.

Presentation Description:

We investigate the problem of automatically determining shoe outsole class characteristics from crime scene impression evidence using computer vision and machine learning techniques. This problem can be formulated as an image retrieval task: given a photo of crime scene evidence, return a ranked list of matching candidates from a database of reference prints. I will describe our approach to automatically extracting tread pattern features using convolutional neural nets and discuss how these features can be robustly compared across images using normalized correlation measures. This framework can be tuned automatically from training data and currently produces state-of-the-art matching performance on benchmark evaluations. Finally, I will discuss some of the challenges in assembling and maintaining a comprehensive database of reference tread patterns.



Forensic Evidence and Forensic Examinations – The Basics

This post is based on the article “Statistical Issues in Forensic Science” by CSAFE Co-Director and Professor of Statistics Hal Stern of Univeristy of California, Irive. Review the full article in the Annual Review of Statistics and Its Application.

When it comes to solving crimes, forensic examiners play a key role in the investigation process and trial proceedings. Their responsibilities vary widely depending on the type of crime and available evidence.

For example, examiners may be called on to identify time of death in a homicide case, reconstruct the events of crime from blood spatter patterns, or take a close look at physical evidence such as broken glass or fingerprints found at the scene. Their analysis of evidence provides crucial details that help in the search for the culprit. The remainder of the discussion here is focused on the role of forensic examiners in attempting to identify if a suspect is linked to particular item of evidence in the case.

It is important to understand that the goal in examining a single piece of evidence is actually not to determine the guilt or innocence of the suspect. Rather, it is an effort to identify if the evidence is associated with the suspect, e.g., if the suspect is a possible source of a fingerprint found at a crime scene. Any number of legitimate reasons could lead to finding evidence from a suspect at the crime scene, such as a visit to the scene at a different time.

Exploring the Different Types of Evidence

  • DNA – DNA found in biological samples recovered at the crime scene is among today’s most powerful forms of forensic evidence. The forensic examiner’s task when analyzing this type of evidence is to determine if the DNA profile of a suspect matches the DNA profile found in the crime scene sample. They then must assess the significance of this agreement.
  • Trace Evidence – Refers to evidence types characterized as a fragment or sample of a larger object that is left behind at the time of the crime. This type of evidence could include glass fragments from a broken window, hairs from an individual, or fibers from clothing or carpet. The challenge here is to determine if a sample of trace evidence from the crime scene matches another sample obtained from a suspect (or perhaps from an object in the suspect’s possession).
  • Pattern evidence – Evidence left at the crime scene that is the result of an impression left by a person or object is known as pattern evidence. The forensic examiner must attempt to determine if the impression found at the crime scene matches the pattern of an analogous sample obtained from the suspect or from an object known to belong to the suspect. Types of pattern evidence include fingerprints, shoeprints, documents/handwriting, toolmarks and firearm impressions.
  • Digital evidence – Digital technology is playing a larger and larger role in criminal and civil investigations. Digital evidence can refer to any information obtained from a device implicated in an investigation. Examples include images or messages found on a smartphone belonging to a suspect. Digital evidence can be challenging to analyze due to the wide variety of different evidence types that may be found on digital devices.

Recent Events Have Raised Concerns About Current Methods

Forensic examiners summarize their evidence analysis in reports that play a crucial role in investigations and trials. Recent events have called into question the scientific and statistical foundations of evidence analysis and interpretation.

This includes the release of two reports, the 2009 National Research Council (NRC) report and a 2016 report of the President’s Council of Advisors on Science and Technology (PCAST), in which committees comprised of scientists from a number of disciplines questioned whether there was sufficient quantitative data supporting the statements made by forensic examiners in a number of disciplines.

Beyond these reports, an additional source of concern is a number of cases in which forensic science errors have been identified. A famous example is the very public case involving American lawyer Brandon Mayfield. Fingerprint examiners from the Federal Bureau of Investigation (FBI) mistakenly identified Mayfield as the source of a latent fingerprint found at the scene of a 2004 train bombing in Spain.

The Innocence Project, a nonprofit legal organization founded in 1992, details countless other situations where unreliable or improper forensic science led to wrongful convictions. The organization has been instrumental in freeing more than 300 wrongfully convicted individuals through the beginning of 2018 and improper forensic science is identified as a contributor in roughly half of these cases.

Why We Need Statistics In Forensic Evidence Analysis

Both the 2009 NRC report and the 2016 PCAST report emphasized the need for additional study of forensic science methods. It is clear that statistical methods have a key role to play in strengthening the scientific foundations of forensic examinations. Statistics is the science concerned with designing studies and experiments, analyzing and interpreting the results, and summarizing the information obtained. As such, it can contribute to studies aimed at determining the accuracy of the conclusions drawn by forensic examiners, addressing cognitive biases, examining the influence of irrelevant information on analysis, evaluating modifications to case processing procedures and more.

This post is based on the article “Statistical Issues in Forensic Science” by CSAFE Co-Director Hal Stern of UCI published in Annual Review of Statistics and Its Application.












Remembering Daubert: A Recap of the CSAFE Symposium on Forensics, Statistics and Law at UVA

This is an invited blog post from Brandon Garrett, CSAFE researcher and White Burkett Miller Professor of Law and Public Affairs and Justice Thurgood Marshall Distinguished Professor of Law at University of Virginia School of Law. Guest blog posts do not necessarily reflect the views of CSAFE.  CSAFE is highlighting this topic due to our team’s commitment to advancing forensic science through enhanced connections between resesarch, statistics and the law.  

Twenty-five years ago, the U.S. Supreme Court ruled in Daubert v. Merrell Dow Pharmaceuticals Inc., that federal judges must conduct a scientific gatekeeping inquiry before admitting expert evidence.  A March 26, 2018 conference at the University of Virginia School of Law explored the challenges and the changes in the law, research and in the practice of forensic science in the years since Daubert was decided. The Virginia Journal of Criminal Law will publish as a symposium issue contributions by experts in forensics, statistics and the law from the event.  The conference was made possible by the Center for Statistics and Applications in Forensic Evidence.

The conference was live streamed and videotaped, with videos available on the UVA School of Law YouTube channel.

Available Sessions:
Forensics, Statistics and Law
Statistics, Research and Forensics
Judging Forensics
Statistics in the Crime Lab
Bringing Statistics into the Courtroom

Opening Remarks Highlights

The conference began with remarks describing how forensic science has changed in the twenty-five years since Daubert was decided and how researchers are beginning to address those shortcomings.  First, Professor Karen Kafadar (UVA) described the importance of statistics to forensic science.  Second, Sue Ballou, Program Manager at NIST, and incoming President of the American Academy of Forensic Science (AAFS), described her career as a forensic analyst and how her work came to engage more over time with questions of statistics and scientific research.  Ballou described, in remarks to be published in the symposium volume, how the CSAFE collaboration and the work of NIST researchers have done more to connect science with forensics. Third, Peter Neufeld described his career, including examples from cases in which he used scientific experts before he co-founded the Innocence Project and began to use DNA testing to free innocent convicts.

Examining How Statistics Applies to Forensic Science

Following those introductory remarks, the first panel discussed the role of statistics in forensic science.  Professor Alicia Carriquiry (Iowa State), whose remarks are to be published in this volume, described importance of statistics in forensics. Hari Iyer (NIST) addressed a different question: assuming there is quantified information about forensics, how are those statistics to be presented in court?  Iyer described recent work with Steven Lund, both at NIST, arguing that there are real concerns with the proposed use of likelihood ratios to express forensic conclusions, including because of the subjectivity of the decisions that are incorporated into such expressions.  Karen Kafadar (UVA), whose remarks are to be published in the volume, described not only the importance of bringing statistical rigor to forensic sciences, but also training on statistics and educational efforts to encourage future statisticians to examine practical and pressing problems in forensics.

Judge Jed Rakoff of the U.S. District Court for the Southern District of New York delivered the keynote address, which is to be published in this volume, asking and addressing why it is that judges have not acted as more forceful gatekeepers in the area of forensic science.

Linda Jackson, Director of the Virginia Department of Forensic Services described how the lab has long made all of its operating procedures available online and works closely with researchers.  Peter Stout, President of the Houston Forensic Science Center, whose remarks are to be published in the volume, described a substantial program to conduct blind proficiency testing in forensic disciplines.  Sharon Kelley (UVA) described case processing data of fingerprint examiner at HFSC, including data on how disagreements between examiners were resolved.  Henry Swofford, of the Defense Forensic Science Center described, in remarks published in this volume, a new program, called FRStat, developed in order to provide quantitative conclusions regarding fingerprint testing.

Investigating the Role of Statistics in the Courtroom

The final panel discussed the role of statistics in the courtroom.  Chancellor and Dean David Faigman (U.C. Hastings) described the need to attend to the connection between general research and individual evidence in criminal cases, as part of a larger question regarding how to associate the general to the individual.  David Kaye (Penn State Law) described several areas in which statistical inferences can be misstated or misleading.  A.J. Kramer, of the Federal Defender, provided a criminal defense perspective, explaining how judges have been almost entirely indifferent to challenges to unreliable forensic evidence, which has in turn discouraged defense lawyers from even raising challenges.  Professor Bobbie Spellman (UVA) argued that to explain forensic evidence to jurors, the goal should not be to train jurors or expect them to be amateur statisticians, but rather to provide them with the information they need to reach statistically sound results.

We could not be more grateful to each of the presenters and contributors to this remarkable Symposium.  We hope that the publications and the remarks themselves are of interest.  Twenty-five years after Daubert more remains to be done to connect research, statistics and the law that governs the forensic science evidence that has become an increasingly integral part of our system of criminal justice.



Forensic Terminology Explained: OSAC Releases New Online Lexicon

Organization of Scientific Area Committees (OSAC) for Forensic Science

Forensic science is a broad field that encompasses a wide variety of disciplines and the roles of forensic examiners are diverse. Each discipline and role comes with its own set of vocabulary, which can quickly become confusing. One word may mean one thing to a DNA analyst, but mean something completely different to a handwriting examiner. The Organization of Scientific Area Committees for Forensic Science (OSAC) has developed a new tool to help forensic scientists speak the same language.

If you are searching for what the word identification really means in forensic science, or want to gain a better understanding of cognitive bias, visit the OSAC Lexicon of Forensic Science Terminology.

The OSAC Lexicon Initiative began in 2016 when OSAC’s Forensic Science Standards Board asked each OSAC unit to identify and collect existing terminology related to their specific forensic science discipline. This database of vocabulary contains 4,000 terms organized by forensic discipline. Users can search by discipline and keyword, using either the term or definition and terms are browse-able by letter. Data is exportable to a CSV file.

Often many definitions exist for the same word, and clicking on the record reveals the source for each term. Readers can rest assured that the information comes from a trusted source. The terms and definitions come from the published literature, including documentary standards, specialized dictionaries, Scientific Working Group (SWG) documents, books, journal articles, and technical reports. In addition, the OSAC subcommittees and committees generated or modified many definitions.

OSAC’s goal for 2018 is to add new terms, remove terms, consolidate duplicate entries, verify sources of non-verified terms, and reach consensus on more OSAC Preferred Terms. Users may suggest a term or submit a comment as the Lexicon continues to evolve.

The Lexicon is a big step forward as OSAC seeks to increase clear communication between forensic scientists.

Digital Evidence: How Technology Changes the World of Crime

Our world today revolves around technology more than ever before. From cell phones to tablets to the latest social media application and beyond, countless opportunities exist for digital communication and entertainment.

The Unique Role of Digital Evidence in Forensic Science

The rise of the digital age has introduced a completely new type of crime. Did you know that every digital device such as a mobile phone or cloud storage is a forensic evidence generator? Each device produces mountains of data, carefully recording our every move. Today, emails, financial transactions, photographs, website browser histories and more can reveal key details in a criminal investigation.

Digital evidence involves a unique investigation process. Other types of forensic evidence analysis like shoeprints or fingerprints focus on comparing if the print left at a crime scene matches that of a suspect.

When forensic examiners investigate digital crime, they turn their attention instead to information that exposes the actions and behavior of the individual.

Key Questions Examiners Ask When Analyzing Digital Evidence

Examiners are interested in exploring a suspect’s intent and motive, and search for clues about a suspect’s location and relationship to the victim or others involved in the crime. To find the answers, examiners must ask several questions when analyzing digital data.

For example:

  • Where is the data stored?
  • Who was using the device?
  • Where did the crime take place?
  • Was the information damaged, destroyed or altered?
  • Are there deleted files that need to be recovered?

Digital evidence analysis focuses on finding the data stored on the device, and making sense of that information. The challenge is using analysis tools correctly, properly interpreting the results and proving the relationship between the individual and evidential data about a criminal activity.

CSAFE Answers the Call to Find New Solutions to Solve Digital Crime

As the digital world continues to change, there is an ever-increasing need for new techniques that allow efficient, accurate analysis and processing of digital evidence.

CSAFE brings together a collaborative task force of statisticians, machine learning researchers, forensic examiners and more to develop statistically based analytical techniques to improve digital evidence investigations. Learn more about our specific research goals on the CSAFE website.

Our team is investigating a wide range of digital evidence areas, from steganography which analyzes digital photos potentially containing hidden content to using mobile apps to solve digital crime. Review a recent CSAFE Center Wide webinar to see how our statistical approach to time-series of user-generated events captured on digital devices is answering questions about this type of data.

In an effort to provide digital evidence examiners with more tools to conduct digital evidence investigations, CSAFE work in digital evidence continues to expand. Discover how our new projects on digital crime scene reconstruction in cyber bulling and investigation of anonymous marketplaces on the dark web is addressing critical needs in digital crime.

As CSAFE and researchers across the country search for better solutions, we are guided by The Organization of Scientific Area Committees for Forensic Science’s (OSAC) recently released report on digital and multimedia evidence in an effort to increase dialog and harmonize core forensic processes across disciplines.

Partner With Us to Improve Digital Evidence Analysis

Are you a digital evidence examiner or do you have research expertise in this area? We want to hear from you! Learn more about our collaboration opportunities and contact us to join us in improving the scientific foundations of digital evidence analysis.