Recording Friction Ridge Exemplars: Traditional vs. Modern Methods

by Kourosh Nikoui | August 7, 2024 | Fingerprints

Friction ridge exemplars, commonly known as fingerprints, have long been a cornerstone of forensic identification. The methods for recording these prints have evolved significantly over the years, enhancing the accuracy and efficiency of fingerprint analysis. This article delves into the traditional and modern techniques used to capture these unique identifiers, exploring their advantages and disadvantages. We also explore the history of fingerprint recording, its adoption as a norm, and the extent of fingerprint databases like those maintained by the FBI.

Historical Background

Early Beginnings:

• First Uses: The use of fingerprints for identification dates back to ancient Babylon, where fingerprints were used on clay tablets for business transactions. However, the first known systematic collection of fingerprints for identification purposes began in the late 19th century.
• Pioneers: Sir William James Herschel, a British colonial magistrate in India, started using fingerprints in the 1850s to identify prisoners. Dr. Henry Faulds, a Scottish doctor working in Japan, and Sir Francis Galton, a British scientist, also contributed significantly to the study and use of fingerprints for identification .

Adoption as a Norm:

• Bertillon System: Before fingerprints, the Bertillon system (anthropometry) was used for criminal identification, based on physical measurements.
• Shift to Fingerprints: By the early 20th century, fingerprints began to replace the Bertillon system due to their uniqueness and reliability. The landmark case of using fingerprints for conviction in 1902 in the United Kingdom played a significant role in this shift .
• Standardization: In 1901, the Fingerprint Branch of the Metropolitan Police in London was established, marking the formal adoption of fingerprints for identification. The use of fingerprints became widespread in law enforcement agencies worldwide by the 1920s .

Traditional Methods

1. Ink and Paper Method

Procedure:

• Preparation: The subject’s fingers are cleaned to remove any dirt or oils.
• Inking: The fingers are rolled on an ink pad to ensure an even coat of ink.
• Recording: Each finger is rolled from one side to the other on a fingerprint card, capturing the ridge patterns.

Pros:

• Simplicity: The process is straightforward and does not require sophisticated equipment and personnel training.
• Cost-Effective: Materials like ink and paper are inexpensive.
• Accessibility: This method can be used in various settings, including remote locations with limited technology.

Cons:

• Messy: Ink can be challenging to handle and may smudge, leading to poor-quality prints.
• Time-Consuming: The process requires careful handling to avoid errors, making it slower.
• Storage Issues: Physical cards take up space and can degrade over time.
• Incomplete Detail: Rolling prints in the traditional way does not capture the entire friction ridge detail. Areas such as the tips of the fingers and the joints are often missed, which can be problematic as many latent prints recovered from crime scenes are made by these areas .

Modern Methods

1. Live Scan Technology

Procedure:

• Preparation: Similar to the ink method, the subject’s fingers are cleaned.
• Scanning: Fingers are placed on a glass plate of a live scan device that captures high-resolution digital images of the prints.
• Processing: The digital images are automatically processed and stored in a computer system.

Pros:

• Accuracy: Digital capture reduces errors such as smudging and incomplete prints.
• Efficiency: The process is faster, allowing for quick capture and immediate transmission or verification.
• Integration: Digital prints can be easily integrated with databases for instant comparison and analysis.
• Storage: Digital storage is compact and durable, with easy access for future use.

Cons:

• Cost: Live scan devices and maintenance can be expensive.
• Technical Issues: The equipment requires regular updates and maintenance, and malfunctions can disrupt the process.
• Training: Operators need training to use the equipment effectively.
• Potential Anomalies: The live scan technology uses a stitching process to compile the entire fingerprint image, which can occasionally cause anomalies or discrepancies. If the finger is not rolled smoothly or there are interruptions during the scan, it might lead to minor misalignments in the composite image. This can sometimes affect the accuracy of the recorded fingerprint .
• Incomplete Detail: Similar to the traditional method, live scan may not capture the entire friction ridge detail, such as the tips of the fingers and the joints, requiring additional techniques for comprehensive recording .

Major Case Printing

Procedure:

• Extended Coverage: Involves recording not just the rolled prints but also flat impressions of the fingertips, sides of the fingers, and areas around the joints.
• Detailed Recording: Ensures that all possible ridge details are captured, providing a more complete representation of an individual’s fingerprints.

Pros:

• Comprehensive Detail: Captures areas often missed in standard recording methods, such as the fingertips and joints, which are critical for comparison with latent prints from crime scenes.
• Improved Identification: Increases the likelihood of matching latent prints with recorded exemplars due to the more extensive detail.

Cons:

• Time-Consuming: The process is more detailed and takes longer than standard recording methods.
• Complexity: Requires additional training and expertise to ensure all areas are correctly captured.

Palm Print Recording

Procedure:

• Full Palm Capture: Involves capturing prints of the entire palm, including the fingers, thenar (thumb) area, hypothenar (pinky) area, and the writer’s palm.
• Ink or Digital: Can be done using traditional ink methods or modern live scan technology.

Pros:

• Additional Data: Palm prints provide more ridge detail, which can be crucial in certain forensic investigations where palm impressions are found at crime scenes.
• Broader Identification: Complements fingerprint records and can be used to identify individuals when fingerprints are not available.

Cons:

• Equipment and Time: Requires additional equipment and time to capture and process the larger surface area of the palm.
• Storage: Larger digital files or physical cards for palm prints require more storage space.

Fingerprint Databases

FBI Database:

• Size: The FBI’s Next Generation Identification (NGI) system, which succeeded the Integrated Automated Fingerprint Identification System (IAFIS), maintains one of the largest fingerprint databases in the world. As of the latest data, the NGI contains over 139 million individual fingerprint records, combining both criminal and civilian prints .
• Usage: These databases are crucial for law enforcement and security purposes, allowing for the quick identification of individuals and cross-referencing with latent prints from crime scenes.

Comparison and Conclusion

Both traditional and modern methods have their place in the field of forensic science. Traditional ink methods, while being cost-effective and straightforward, suffer from limitations in quality and efficiency. Modern live scan technology offers superior accuracy and speed, making it the preferred method in many forensic applications today. However, the high cost and need for technical expertise can be barriers to widespread adoption, especially in resource-limited settings.

Major case printing and palm print recording are essential for comprehensive forensic analysis. These methods capture areas of friction ridge detail often missed by standard techniques, enhancing the ability to match latent prints found at crime scenes. Despite occasional anomalies due to the stitching process in live scan technology, the overall benefits significantly outweigh the drawbacks, making it a critical tool in modern forensic investigations. As technology continues to advance, hybrid approaches and improvements in digital systems are likely to further enhance the process of recording and analyzing friction ridge exemplars, ensuring more reliable and accessible forensic identification.

Forensic Investigator and Specialist Kourosh Nikoui, Principal Consultant and CEO of Nikoui & Associates, Forensic Identification Services & Consulting, Inc., has over 38 years of full-time experience in forensic science and criminal justice with various law enforcement agencies, government and private entities. Mr. Nikoui, a court-qualified expert, is a Certified Latent Print Examiner, Certified Senior Crime Scene Analyst, and Certified Forensic Photographer by the International Association for Identification. He has testified as an expert witness over 150 times in California Superior and U.S. Federal Courts, processed evidence in over 30,000 criminal and civilian cases, and served as a consultant to numerous law enforcement agencies. Mr. Nikoui holds a BFA degree from USD and is an active member of multiple forensic science organizations. He can be reached directly by calling (866)439-6753 or by email at [email protected]

References

1. Meier, Allison. “Fingerprinting Through the Ages.” Mental Floss. Available from: link.
2. Welling, William. “Photographic Origins: The Birth and Growth of Photography.” Hastings House Publishers.
3. Cole, Simon A. “Suspect Identities: A History of Fingerprinting and Criminal Identification.” Harvard University Press.
4. “History of Fingerprints.” Crime Scene Forensics. Available from: link.
5. Ashbaugh, David. “Quantitative-Qualitative Friction Ridge Analysis: An Introduction to Basic and Advanced Ridgeology.” CRC Press.
6. “Live Scan: Electronic Fingerprinting.” Integrated Biometrics. Available from: link.
7. Garris, Michael D., Watson, Craig I., and Hicklin, R. Austin. “The Effects of Fingerprint Image Compression on Matcher Accuracy.” National Institute of Standards and Technology (NIST).

“Next Generation Identification (NGI).” FBI. Available from: link.