Course Description
Many investigators – let alone fingerprint examiners – are either unaware of the entire world of possible identifying evidence contained in inadvertently photographed hands and other ridge-detail areas, or unsure how to utilize this type of modern evidence. In our current society, digital cameras are everywhere and used constantly – from everyday snapshots to images posted on social media and websites. Just like regular citizens, criminals take images of a multitude of objects, people, and locations. These images can be discovered during routine online investigations or whilst executing search warrants. Some images are occasionally deemed incriminating – such as a felon holding a firearm in their hand, or a pedophile with their hand visible in a compromising position. However, these images can usually only be used as evidence (or at the very least much stronger evidence) if an identification can be made to the ridge detail visible in the image.
There have already been several cases involving the identification of people using ridge detail visible in photographs, both across the USA and internationally. Such cases where identifications were made from inadvertently photographed ridge detail include rape, pedophilia, firearms, drugs, and burglaries.
Understanding this increasingly common type of evidence is critical for the modern-day fingerprint examiner. Knowing how to adjust perspective, how to appropriately calibrate the fingerprint to scale, and how to enhance these types of images to properly visualize ridge detail gives examiners important skills for their toolkit to assist with new investigative methods. Furthermore, being able to advise investigators of the value of this type of evidence will be possible once examiners know what is achievable.
Prerequisites
Having prior basic knowledge of Automated Fingerprint Identification Systems (AFIS).
Course Logistics
Should be Able to Perform
- Recognize the potential evidentiary value of social media and other inadvertent photographs of friction-ridge detail areas.
- Apply key image enhancement techniques required for this type of evidence.
- Apply advanced techniques to correct the perspective for ridge detail on a non-perpendicular plane.
- Correct for the distorted appearance of ridge detail curved around a finger/hand, so that it more closely represents the 2-dimensional appearance of friction ridge detail in tenprint exemplars.
- Be able to utilize multiple methods of appropriately recalibrating digital images to correct scale, even when a scale/ruler is not present in the image, to allow for accurate AFIS searching.
Must Bring to Class
A computer with access to Photoshop is required for this course and is needed to complete some of the exercises successfully. Adobe offers free trial versions of Photoshop on its website.
Photoshop version 22.3 or earlier should be installed, as later versions have affected the 3D space used for the vanishing point filter. We highly recommend turning off Photoshop auto-updates. Alternatively, you can install BOTH the current version of Photoshop AND version 22.3 from the Creative Cloud. It costs no extra money beyond your Photoshop subscription, and both programs can run independently on your computer. This way, you can use the current version for all tasks and switch to version 22.3 only when you want to use the vanishing point filter.
Course Objectives
- Module 1 – Social Media Fingerprints
- Case Studies 1‐8
- Additional Research & Audit Trail
- Module 2 – Image Enhancement and Correcting Perspective
- Step 1 – Lateral Reversal
- Practical Exercise 1
- Step 2 – Tonal Reversal
- Practical Exercise 2
- Step 3 – Image Enhancement
- Practical Exercise 3
- Step 3a – Correct Orientation
- Practical Exercise 3A
- Step 4 ‐ Perspective
- Practical Exercise 4
- Step 1 – Lateral Reversal
- Module 3 – Searching for Social Media Fingerprints
- Module 3A – Image Recalibration Methods
- Module 3B – Image Recalibration in Photoshop – Using Ridge Count
- Practical Exercise 5
- Module 3C – Image Recalibration in Photoshop – Using Objects and Hand Dimensions
- Practical Exercise 6
- Practical Exercise 7
- Module 4 – Putting It All Together
- Practical Exercise 8
- Desk Reference PDF
- Adjustments/Enhancements
- Correcting Perspective
- Recalibrating to Scale for Searching in AFIS
Course Expectations
Students in this class will gain historical knowledge of cases in which inadvertent friction ridge detail visible in photographs has been used in investigations. This, in turn, enables the student to advise and educate investigators on this type of evidence.
Students will learn the key enhancement techniques required for any inadvertent photograph of ridge detail. This includes several methods to properly recalibrate the image to scale for accurate AFIS searching.
Ultimately, students will be armed with new knowledge and skills to confidently process, analyze, and identify inadvertent ridge detail in social media photos and other digital images.
Students will be required to complete a quiz at the end of the course to ensure they have properly understood the course content and participated appropriately.
Training Certification and Recertification Credits
ONLINE - Social Media Fingerprints and Other Inadvertently Photographed Ridge Detail may qualify for specific continuing education training credits. Use's summary below as a quick reference for organization and discipline specific applicability. The approving organization has final authority and their website should be referenced before submitting any request for training credits.
International Association for Identification (I.A.I.) Latent Print Certification Board Approved for 8 Certification Credits
International Association for Identification (I.A.I.) Latent Print Certification Board Approved for 8 Re-Certification Credits