Trace evidence includes hair, fibers, glass, soils, particles, explosives and any small items found at a crime scene. You should always verify that proper procedures were followed and protocols were not breached. Evaluation of potential evidence prior to reaching the courtroom will help you assess the value of the evidence and whether procedures were followed to yield accurate results.
Daubert considerations should also be evaluated prior to entering the evidence or expert testimony.
Striations by definition are marks, grooves, furrows or ridges that are caused when a cutting blade passes through an object such as a stack of paper. Striations are the result of defects, flaws or wear characteristics in a particular blade.
A study and comparison of striations can result in the identification of a particular blade.
In addition to seizure of the cutter, it is imperative that sample cuttings be obtained from the cutter utilizing the entire length of the blade. Sample cuttings should be made using paper that is similar to that which was used to print the questioned documents.