Forensic Document Examination Notes

Forensic Document Examination (FDE)

  • Definition: A forensic science discipline where expert examiners evaluate disputed documents to determine their authenticity and integrity for use in the legal system. FDE encompasses a variety of techniques used to analyze handwriting, inks, printing methods, and other aspects of documents to assess their validity, particularly in cases of forgery, fraud, and alterations.

Standards of Practice

  • ASTM Standards: The American Society for Testing and Materials (ASTM) establishes rigorous standards for FDE methods and procedures to ensure reliability and accuracy in assessments.

  • Purpose of Examinations:

    • Establish the genuineness of documents or detect forgery, alterations, or omissions.

    • Identify or eliminate potential sources of handwriting and typewriting through comparative analysis.

    • Generate detailed reports or testify in court to clarify findings and methodologies for judges and juries.

  • Guidelines: Developed by the Scientific Working Group for Forensic Document Examination (SWGFED) and Scientific Working Group Document Examination (SWGDOC), these guidelines include best practices for quality assurance, proficiency testing, and standardized procedures, ensuring consistency in the examination process.

Techniques in Document Examination

  • Light Source Analysis:

    • Involves both normal viewing and infrared luminescence to reveal alterations in documents, such as determining if a check has been modified from $1,000 to $9,000 by visualizing the changes not discernible under standard light.

  • Visible Light:

    • Provides insight into surface characteristics where alterations may show under normal viewing conditions, allowing examiners to identify discrepancies between original and altered documents.

  • Infrared Light:

    • Different inks respond distinctly to specific infrared light frequencies, facilitating the identification of alterations in documents. This technique is particularly useful in revealing pen or print changes that are invisible to the naked eye.

Analyzing Inks and Toners with FTIR Microscopy

  • Infrared Images: Used to analyze banknotes and other critical documents, relying on identifying peaks related to calcium carbonate and other ink components. This method significantly enhances the ability to differentiate inks based on their chemical signatures.

  • Identification of Inks:

    • Comparing ink signatures and chemical compositions through Fourier Transform Infrared Spectroscopy (FTIR) to determine the types of inks used, which is crucial in cases of document forgery.

Databases for Document Analysis

  • U.S. Secret Service:

    • FISH Database: A comprehensive collection containing extensive handwriting samples gathered from various sources, which aids in identifying authorship in disputed documents.

    • International Ink Library: Houses over 15,000 ink records chronicled since 1920, facilitating accurate identification of inks used in documents.

  • Functionality: Engaged in scanning, digitizing, and comparing handwritten documents to establish matches or discrepancies, which is vital for accurate forensic analysis.

Limitations of Forensic Document Examination

  • Non-original Evidence: Photocopies or faxes often lack essential information; original defects may not be replicated, thus complicating the authenticity verification process.

  • Insufficient Material: A lack of adequate quantity or quality of sample documents can hinder definitive conclusions, causing a reliance on subjective interpretations.

  • Comparability Issues: Writing styles need to be compatible for a fair comparison, and dissimilarities can lead to misinterpretations.

  • Quality of Known Samples: Insufficient or poor-quality reference samples can significantly impede the accuracy of comparisons, affecting the overall validity of results.

  • Temporal Relevance: Known samples should ideally be contemporaneous with questioned documents to maintain the integrity of the examination.

  • Distortion or Disguise: Excessively distorted writing styles make effective comparison difficult, as evidenced in graffiti where intentional changes obscure natural handwriting features.

NAS Report on Handwriting Analysis

  • Terminology Development: Aims to codify subjective conclusions in handwriting comparisons with a structured multi-point scale, including a Nine-point Scale to provide clear gradations of certainty:

    1. Identification

    2. Strong Probability

    3. Probable

    4. Indications of same author

    5. No Conclusion

    6. Indications of different authors

    7. Probably did not

    8. Strongly probably did not

    9. Elimination

  • Strengthening Scientific Basis: There is a critical need for robust research to enhance the reliability and validity of handwriting comparison techniques, addressing concerns raised in the legal field regarding the evidentiary weight of such analyses.

Case Studies in Forensic Document Examination

  • Example 1: R. v. Dobis - Involvement in forged checks totaling significant amounts highlights the critical role of document verification in fraud detection.

  • Example 2: R. v. Fairbarn - A multi-count indictment involving forged prescriptions demonstrates the challenges faced in identifying fraudulent behavior within the medical field, emphasizing the need for accurate forensic document examination to uphold integrity in healthcare.

Security Features in Documents

  • Classification Levels:

    • Level 1: Verification through human senses, such as visual inspection of surface features.

    • Level 2: Basic tools like UV lamps and magnifiers for enhanced analysis.

    • Level 3: Utilization of specialized forensic tools, including microscopes and video spectral comparators for in-depth examinations.

    • Possible 4th Level: Secret features known only to manufacturers, which complicate counterfeit attempts and enhance document security.