The digital computer and the
laser printer have altered the world of evidence in ways that have
not yet been fully perceived by personkind—let alone the law.
Digital computers have created an evidentiary
dichotomy: on the one hand digitized text, images and audio are
immortal, existing for as long as their creators wish, and on the
other hand they are completely plastic, subject to change on a whim.
Laser printers, working in concert with digital
computers, have made a nonsense out of the concept of an "original
document"—an original is indistinguishable from subsequent
A laser printed document (or even a document
produced by an alternative marking engine) can raise several questions:
When was this document printed? By whom was it printed? Which printer
was used to print this document? Was this document tampered with
after its original printing? Was a given page printed on different
paper from the other pages?
Using a combination of photomicrography,
and photometrics, JLI can examine questioned documents and provide
answers to some of these questions.