All courses listed below are approved for IAI Latent Print Certification and Re-Certification training hours.

Please see the Webinar Schedule for Dates and Times



Discriminating Power of Friction Ridge Arrangements (4 hours)

Instructor: Alice White

Did you know the suggestion that “ridge units line up to form ridges” is based on a historical theory proposed in biology in the 1800’s called the theory of recapitulation? Although the theory of recapitulation was handed a death knell in the mid-1900’s by the budding field of genetics, the idea that “ridge units line up to form ridges” continued into the afterlife via the friction ridge discipline. In reality, embryologists have never observed ridge units lining up to form ridges in the friction ridge skin.

Did you know there are three factors (genetics, environment, and developmental noise) that are cited by biologists as causing variation in any trait, including the features in the friction ridge skin? When studying biological sources of variation in any given trait, “differential growth” is not listed as a reason. Why? Because “differential growth” does not mean “variable” or “unique”.

These misconceptions and more will be addressed as this lecture explores the following questions: Based on actual observations from embryologists, what is the sequence of events that leads to the formation of the friction ridge skin? What is developmental noise? What is developmental stability? What is fluctuating asymmetry? Why are some aspects of the friction ridge skin useful for determining the anatomical origin (finger, palm, foot) and distal orientation (up) of a latent print? Why are the arrangements of the ridges in the friction ridge skin highly discriminating? Which features of the friction ridge skin do twins tend to share in common and why? Why do people have different fingerprints on their own fingers? Why do pattern force regions tend to have a high density of common minutiae (ending ridges and bifurcations) all pointing the same direction? Why do thumbs and index fingers have more minutiae, and more variety of complex minutiae, than the other fingers? Everything starts with the skin…


Beyond Discriminating Power of Friction Ridge Arrangements – Applying What You Learned (4 hours)

Instructor: Glenn Langenburg

In this course, we will apply the fundamental concepts highlighted in “Discriminating Power of Friction Ridge Arrangements”.  We will explore different examples of friction ridge patterns and arrangements, and demonstrate, using the power of a statistical model, which arrangements display a higher specificity than other arrangements.  We will see how various regions of the finger, different pattern types, different minutiae types, and clarity can all impact their discriminability.  Participants will have a chance to analyze latent prints and guesstimate specificity using their ‘training and experience’ factor (e.g. ‘subjective probability’). Then we will compare our predicted results to output results from a statistical model that uses an AFIS database (approximately 1 million fingerprints) to estimate the relative specificity for given configurations.  These are excellent practical exercises to calibrate your ability to assess specificity.  We also explore how these principles impact close non-matches and observe in a data-driven manner how close non-matches are designed to fool us from a specificity perspective.


Limits of Persistency in the Friction Ridge Skin (4 hours)

Instructor: Alice White

This webinar is adapted from elements of the Analysis of Distortion in Latent Prints workshop that Alice has taught since 2006. In this webinar Alice will introduce the changes that take place in the friction ridge skin throughout your lifetime. Tenprint and latent print examiners should be aware of the limits of the persistency of the various features of the friction ridge skin.

The first changes actually take place in the skin as the hands and feet grow to their adult size. Did you know that some ridges will predominantly grow in length while others predominantly grow in width? This growth process actually alters certain aspects of the friction ridge skin.

During the busy lifetime of an individual, the skin can change due to injuries and disease. Sometimes these issues are temporary, and the skin returns to the “pre-injury” or “pre-disease” state. Other times however, injuries can alter ridge patterns, ridge paths, and minutiae.

As people pass through middle age, changes occur once again. Did you know that incipient ridges tend to blossom in the furrows throughout your lifetime? Are you aware that the ridges themselves tend to change in length and width and that ridge edge shapes often change dramatically with age?

This lecture will provide numerous examples and explain how these changes take place. This will help friction ridge examiners to 1) recognize common changes in the friction ridge skin, 2) recognize the conditions under which to expect these types of changes and 3) explain differences caused by these changes based on the anatomy and physiology of the friction ridge skin.


Examination of Friction Ridge Impressions (4 hours)

Instructor: Alice White

Any discussion of training, testing, technical review, conflict resolution, process improvement, and errors must first start with an adequate description of the ACE-V process. Over the years, the comparison process has frequently been over-simplified to Level 1, Level 2, and Level 3 Details with “agreement” and “disagreement” during a side by side comparison. This over-simplification leaves tremendous gaps in the examination process. Those gaps become pitfalls for the analysts.

Alice White will present a more nuanced discussion of the ACE-V process that provides a pathway for the development of training programs and quality management systems. This discussion of the examination process will include: 1) definitions of the macroscopic and microscopic features available in friction ridge impressions; 2) expected discriminating power of each macroscopic and microscopic feature based on embryological development or random acquisition; 3) sources of variation in appearance (distortion) of each macroscopic and microscopic feature; and 4) the useful (and necessary) heuristics analysts must learn in order to effectively examine friction ridge impressions.

For casework examiners, the numerous examples of the various friction ridge features and their variations in appearance will serve as a vital reference. For technical leaders and managers, the more nuanced discussion of the ACE-V process will open pathways for the improvement of training programs and quality management systems.


Implementing the Expanded OSAC Conclusion Scale (4 hours)

Instructor: Glenn Langenburg

In this course we will review the 2018 OSAC proposed standard “Standard for Friction Ridge Examination Conclusions” and outline how to introduce and implement this standard into your ISO accredited procedures.  We will explore the importance of qualitative versus quantitative results, relative magnitude, and how to understand the significance of these terms.  We will define these terms and how they differ from current terms.  Glenn will propose methods for testing the use of this scale and what is required to implement the standard into casework in an accredited agency.  Attendees will have an opportunity to apply these terms to practical examples and discuss the pros and cons of using an expanded scale of conclusions.  Furthermore, we will discuss how to manage conflict resolution under this reporting scheme.  Finally, we will look at specific reporting examples and courtroom testimony questions and responses.


Resolving Conflict in Friction Ridge Examinations (3 hours)

Instructor: Glenn Langenburg

Conflicting opinions in friction ridge examinations are an inevitable event. Someagencies do not have a policy for resolving conflict; some that dohave themare not very specific.How are examiners supposed to “see if they can resolve the conflict” if there are not specific recommendationsand clear instructions for doing so?This webinar explores concrete methods for resolving conflictand deciding what to report.We will use case examplesto illustrate specific scenarios and how to resolve them.


Basic Fingerprint Distortion (4 hours)

Instructor: Alice White

This webinar is adapted from elements of the Analysis of Distortion in Latent Prints workshop that Alice has taught since 2006. In this webinar Alice will introduce basic concepts in contact mechanics (what happens to the skin when it makes contact with a surface) and the transfer of friction ridge features to impressions under four common circumstances.

We will explore basic touches under different deposition pressures and evaluate the changes in the following: overall size and shape of a fingerprint, ridge and furrow width, feature type, edge shapes, incipient ridges, and wrinkles/secondary creases.

Further, we will explore anomalies and difficulties presented by skin that wobbles on the surface, double touches/overlays, and double taps. Numerous images and videos will be used to illustrate these commonly encountered distortions.

While this class is titled “Basic”, this course covers some challenging interpretation issues related to tonal issues created when the skin wobbles on the surface, sources of false minutiae, and the illusion of continuity created by double touches and double taps.


Advanced Fingerprint Distortion (4 hours)

Instructor: Alice White

This webinar is adapted from elements of the Analysis of Distortion in Latent Prints workshop that Alice has taught since 2006. In this course Alice will introduce the anatomical structures of the finger that influence the behavior of the friction ridge skin when it moves on a surface.

After reviewing basic concepts and terminology in contact mechanics, attendees will learn how the skin behaves under four different types of shearing stress. For each type of shearing stress, the attendee will be able to view videos of the skin deforming as it slides on the surface and the resulting latent print.

In some of the most complicated samples, Alice will demonstrate what happens when shearing stress is accompanied by changes in compressive stress or angle of contact. The possible risks of treating these impressions “as one impression” will be discussed and examples provided.

Important lessons from this webinar include 1) sources of missing or false minutiae and 2) how the effects of shearing stress lead to incorrect interpretation of deposition pressure.


Tonal Transitions: Causes and Visual Effects (4 hours)

Instructor: Alice White

This webinar is adapted from elements of the Analysis of Distortion in Latent Prints workshop that Alice has taught since 2006. Ideally, the ridges in the friction ridge skin contact a surface and transfer an even coating of residue to the surface. This residue is then targeted by a latent print development technique, resulting in an impression that has distinctive ridges and furrows that require minimal eye strain to follow. But the world of latent prints is rarely so neat and tidy.

In this webinar we will look at many ways the ridges and furrows stray from this ideal condition. We will first discuss the composition of latent print residue (research has demonstrated it is NOT 98-99% water – we will dive into the source of this misconception). We will then discuss the different ways residue can be distributed across the surface of the skin and how this distribution matters when a surface is touched.

After contact with a surface has been made, the manner in which the skin slides through the residue wreaks all kinds of havoc on the tone of the ridges and furrows – we will explore the many visual anomalies associated with movement. Lastly, we will discuss the impact of surfaces that already have contaminants and how this affects the transfer of residue, and consequently the appearance of the ridges and furrows.


Examination of Bloody Friction Ridge Impressions (4 hours)

Instructor: Glenn Langenburg

Blood matrix can be one of the more difficult factors affecting the interpretation of friction ridges. Owing to its unique composition, blood creates many unusual artifacts in friction ridge impressions. We will examine the range of bloody impressions from liquid, to tacky, to nearly dry. Furthermore, we will examine the typical characteristics that manifest in bloody impressions. We will watch the moments blood impressions are deposited and what happens to them as they dry. Finally, we will review the literature and research regarding ‘activity level’ statements such as if a bloody impression was made in blood or made with blood.


The Trouble with Exclusions (4 hours)

Instructor: Alice White

This course will use three regions of the friction ridge skin to demonstrate the difficulty with exclusions: extreme tips of fingers, extreme edges of fingers, and impressions from proximal and medial phalanges. These regions will illustrate the importance of understanding the completeness of exemplar prints and appropriate conclusions.

With tips and edges of fingers we will focus on the challenge of approximating the distance and angle to the core or a delta. With the lower segments of the finger we will focus on the challenges of determining 1) medial from proximal segment, 2) lateral position along the segment, and 3) variation in the recording of the secondary creases.

In addition to these problematic areas of the friction ridge skin, Alice will demonstrate same source samples that would likely result in a high false exclusion rate simply due to the differences caused by distortion. Attendees should leave this webinar with a better grasp of why the false exclusion rate will likely always be higher than the false identification rate.


Introduction to Palm Prints (16 hours)

Instructor: Alice White

This four-part webinar (spread over 4 days) is dedicated to the friction ridge skin of the palms. Each region of the palms has distinctive ridge flows, patterns, deltas, and creases that can be exploited to determine the anatomical sub-region, left/right handedness, and distal orientation of partial impressions (e.g. latent prints). Additionally, deltas and patterns on the palms have distributions within the population that inform the rarity of these features during the ACE (Analysis, Comparison, and Evaluation) process.

During the lecture we will cover each region of the palm and attendees will practice left/right hand determinations. After the lecture, attendees will have region-specific comparison exercises to complete before the next day. A challenging, mixed region, palm print comparison will round out the last day. This webinar summarizes original palm print data published by Alice (Maceo) White in the Encyclopedia of Forensic Science.


How to Prepare for a Latent Print Daubert Hearing (4 hours)

Instructor: Glenn Langenburg

In this course, we will learn helpful strategies for preparing for admissibility hearings.  We will learn the difference between Frye and Daubert hearings (or 702 hearings or equivalent). Glenn will demonstrate different strategies for addressing ‘general acceptance’ of fingerprint methodology.  We will review various peer-reviewed research papers that demonstrate ‘testing and validation’ of fingerprint methodology.  We will review industry standards that are available to the analyst.  Critical error rate studies will be discussed and we will review a strategy for addressing the known or potential error rate of latent print methodology.  Finally, we will examine some limitations of fingerprint methodology which need to be acknowledged.


Importance of Expertise in Friction Ridge Examinations (4 hours)

Instructor: Alice White

What is an expert? Not in the legal sense, but in the cognitive sense. Why was it difficult to look at prints when you first started as a trainee, but now it is easier? Why are some types of distortion issues difficult to decipher, no matter how many years you have been looking at prints? How does your visual system, finely tuned over many years of looking at prints, behave differently than a novice’s? Why do you see and know things about a print that a novice cannot possibly see and know? Ultimately, why does your expertise matter when it comes to examining friction ridge impressions? And why does your expertise sometimes lead you to a different conclusion than your coworker’s expertise?

There are two reasons impressions of the friction ridge skin are a valuable means of identification 1) the features present in the friction ridge skin are highly discriminating and reasonably persistent and 2) trained examiners have expertise that increases their conclusion accuracy well above novices. This webinar addresses the science behind the development and limitations of visual expertise in examiners. Alice will cover basics of vision science and the data that demonstrates the types of visual expertise attained through training and experience. Know the friction ridge skin, but also “know thyself” [Temple of Delphi].


Modeling Fingerprint Minutiae (4 hours)

Instructor: Alice White

This webinar takes a deep dive into the challenges associated with modeling the behavior of minutiae in a fingerprint. These challenges have resulted in the largely unstable performance of many fingerprint statistical models. Alice will present a brief overview of how scientists use mathematics to describe and predict the natural world.

From this general discussion, the lecture will cover the fundamental differences in the markers modeled for forensic DNA analysis (alleles) and the markers modeled for fingerprints (minutiae). The lecture will then turn to the findings from three key studies that illustrate the incredibly complicated dependencies of minutiae in fingerprints.

Once these dependencies have been described, Alice will provide a general overview of fingerprint statistical models. If you have ever been asked or if you have ever wondered, “Why aren’t you providing population statistics like DNA?” This webinar will help you understand.


Managing Cognitive Bias in Friction Ridge Examinations (3 hours)

Instructor: Glenn Langenburg

Now, more than ever, forensic service providers are required to demonstrate their commitment to impartiality (ISO/IEC 17025:2017 4.1). This training addresses this issue by exploring how cognitive bias can influence friction ridge examinations. In this 3-hour course, we will identify potential sources of cognitive bias in friction ridge examinations and examine how it may impact our decision-making. We will review the current literature on this topic and critical findings. To see how bias can impact our casework we will review fingerprint cases (some famous, some not) where bias contributed to the error or the management of the error. Lastly, we will identify specific actions, best practices, and procedures that you can adopt to minimize the impact of potential bias. Attendees of this course will be provided with specific examples of how to conduct blind examinations, case-manager models, and sequential unmasking approaches.


Error Rates, Human Factors, and Quality Management Systems (4 hours)

Instructor: Alice White

This webinar will review selected error rate studies, including PCAST’s use of confidence intervals to estimate the range within which actual error rates could fall for specific studies. Error rates may be meaningful for the courts assessing general reliability of friction ridge examinations, but they are not terribly helpful when assessing errors in casework.

From the discussion on error rates, Alice will walk attendees through the many human factors that can contribute to errors. Once the landscape of pitfalls has been illuminated, Alice will review the checks and balances within a quality management system that enhance analyst performance and reduce error rates even lower.

Ultimately this webinar should prepare attendees for testimony issues related to error rates and prompt agencies to consider a more nuanced human factors approach to dealing with mistakes and errors.