Tuesday April 10, 2018 (Document Evidence Part 2 – Alterations, Erasures, Obliterations, and other Document Problems)

The Daily CSI 1/1 Tuesday, 4/10/2018 When paper chromatography is used to separate the component pigments of black ink, why do some colors travel further up the paper than others? Some of the colored pigments dissolve in the water more readily than others, so they travel further up the paper.

We will take Quiz 15 on Friday! Announcements We will take Quiz 15 on Friday!

3/29 N/A 4/6 4/9 Friday, 4/20 F5 F6 F7 Assignment Summative or Formative # Date Issued Gone Missing Day Last Day Accepted XC Current Events Crossword F5 3/29 N/A Friday, 4/20 eResearch Paper – The Forensics of Document Examination F6 4/6 LAB – Paper Chromatography of Inks F7 4/9

Document Evidence (Part 2) Alterations, Erasures, Obliterations, and Other Document Problems

Alterations, Erasures, Obliterations, and Other Document Problems Altered documents are those that have been changed after preparation to hide their original intent or to perpetrate a forgery. Documents can be changed in several ways, and for each way the application of a special discovery technique is necessary.

Alterations, Erasures, Obliterations, and Other Document Problems Documents examiners deal with evidence that has been changed in several ways, such as through alterations, erasures, and obliterations.

Alterations, Erasures, Obliterations, and Other Document Problems Infrared luminescence can be used to detect alterations to a document made with ink differing from the original. Infrared luminescence can also reveal writing that has been erased or obliterated.

Alterations, Erasures, Obliterations, and Other Document Problems A digitized image can be lightened, darkened, and color and contrast adjusted with appropriate software.

Alterations, Erasures, Obliterations, and Other Document Problems It may be possible to read indented writing – the impression left on a paper pad – by applying an electrostatic charge to the surface of a polymer film that has been placed in contact with a questioned document.

Alterations, Erasures, Obliterations, and Other Document Problems Studying the chemical composition of writing ink present on documents may verify whether known and questioned documents were prepared by the same pen.