Forensic tools Used By Document Examiners

Summary

The presenter describes tools used by forensic document examiners to inspect, capture, measure, and compare documents while preserving the originals. These tools help examine handwriting, signatures, ink, and impressions left on pages beneath those that were written on.

Tools and their uses

• Digital microscope: A high-end microscope can be held over a document to capture magnified images directly on a computer. The presenter uses a Mycope digital microscope, made by Zarbec in New Jersey, for some of the images shown.
• Optical microscope: A conventional microscope with a boom arm lets the examiner position the viewing lens above the document, making the page easier to inspect.
• Infrared and ultraviolet scopes: These use different wavelengths of light to examine features that may not be visible under ordinary lighting.
• Loupe: A small magnifier, typically offering about 10× to 20× magnification, provides a simple way to inspect details closely.
• NIST rulers: Standardized rulers, graduated to 1/64 of an inch, are used to measure handwriting for comparative analysis.
• Adobe Photoshop: Images captured by microscope or scanner can be enlarged, recolored, cropped, or overlaid. For example, overlaying signatures can help compare their similarities.
• Computer and flatbed scanner: Scanning stores a document image for later examination and editing. Working with a digital copy lets the examiner manipulate the image without altering the original. If an edit damages the working image, it can be discarded and the document scanned again.
• ESDA (Electrostatic Detection Apparatus): This equipment reveals indented writing, such as impressions left on a page beneath one that was written on. Those impressions may help determine what was written on a page or whether a page was removed. The presenter describes the equipment as expensive, with a base price of roughly $7,000 and higher-end units costing $20,000 or more.
• VSC (Visual Spectral Comparator): This equipment examines documents under ultraviolet and infrared light. The presenter says both the VSC and ESDA can assist with difficult document questions.

Examination challenges

Determining which of two intersecting lines or writings was made first can be complex. ESDA and VSC examinations may help, but the presenter emphasizes that the problem is difficult and has been the subject of research.

For example, an examiner may need to determine whether a signature was placed before or after writing that crosses it. The order could affect whether the signature appears to authenticate the writing.

Ink behavior can make sequence judgments tricky. In examples with a known writing order, examination under a microscope may appear to suggest the opposite sequence. The presenter cautions that visual appearance alone may not settle the question.

Speakers and sources featured

• Speaker: Mike Wakshull, identified in the video context as the presenter.
• Organizations and manufacturers mentioned: Zarbec (maker of the Mycope microscope, as named in the subtitles); NIST; Foster + Freeman (manufacturer of the ESDA and VSC, as named in the subtitles); and Adobe (maker of Photoshop).