Sequence determination

A sequence determination is a type of examination conducted by a forensic document examiner.^[1] This type of forensic examination is done in an attempt to determine which of two events occurred first in the preparation of a document. Another term used for this type of examination is "sequence of intersections" since the evaluation requires intersection of physical materials on the document.

Types

• Sequence of Strokes: term for examinations involving two or more writing strokes from one or more writing instruments
• Sequence determinations for writing ink with other types of material:
  • Ballpoint pen ink/toner sequence
  • Ballpoint pen ink/inkjet ink sequence
  • Writing instrument/paper fold sequence
  • Writing instrument/typewriting sequence
• Other sequence determinations:
  • Toner/paper fold sequence

Methods

The primary means of evaluation involves direct visual examination using microscopy and various lighting options. The intersection point may involve subtle deviations from the normal manner of deposition or production that can be observed on microscopic examination (e.g. extraneous ink deposits, skipping, misalignents, embossing, etc.). Lifting/casting technique (see below) have also been tested with some success. Intersections involving indentations may also be assessed using an electrostatic detection device to visualize latent indentations.

• Binocular optical microscopy
• Scanning electron microscopy
• Atomic force microscopy
• Lifting techniques
  • Kromekote paper method^[2]
  • Mikrosil casting method^[3]
• Electrostatic detection device (EDD) method^[4]

Significance

The underlying concept is that each of the sequences will produce a distinctive result that can be visualized or measured.

In some instances, the results will be essentially conclusive with only one reasonable interpretation. In other situations, the results may be less definite in that the observed features may permit more than one interpretation of the original sequence.

References

1. ASTM Standard E444-09 (Standard Guide for Scope of Work of Forensic Document Examiners) indicates in section 4.2.1.4 that the work of a forensic document examiner includes "The establishment of the date, source, history, sequence of preparation, alterations or additions to documents, and relationships of documents". Copies of ASTM Standards can be obtained directly from ASTM International.
2. Igoe, T.J.; Reynolds, B.L. (1982), A lifting process for determining writing sequence of two intersecting ball-point pen strokes, 20, Forensic Sci Int, p. 201
3. Binette, J.; Barton, A.; Ostrum, R.B. (Sep 2, 2010). "Toner and Ballpoint Pen Line Crossing Determination Using Mikrosil Casting Medium". 2010 ASQDE Annual Meeting. Victoria, BC.
4. "Indented impressions". LGC Limited. Retrieved February 2011. In more complex cases the order that writing and indentations were made may be deduced providing significant information regarding a sequence of events. Check date values in: |access-date= (help)