Technology Used in Handwriting Analysis Biometric Signature Pads

Technology Used in Handwriting Analysis Biometric Signature Pads l l This computerized pad “learns” to recognize how a person signs his or her name based on the speed, pressure, and rhythm of the signing. Forgeries then are recognized by the detection of even slight differences. Computerized Analysis of Handwriting l l 1 Computers can make objective comparisons between handwritings. Suspect signatures can be compared with ones stored in databases. Forensic Science: Fundamentals & Investigations, Chapter 10

Handwriting Evidence in the Courtroom l The expert shows how comparisons were made. l The defense attorney likely will cross-examine the handwriting expert. Shortcomings in Analysis l A particular piece of handwriting can be different from its usual style because of factors such as fatigue. l Experts can miss details. 2 Forensic Science: Fundamentals & Investigations, Chapter 10

Secret Service l l l Started by Lincoln as one of his last acts in 1865 Developed to prevent counterfeiting Almost 1/3 of money was counterfeit Became a protective agency in 1900 Now under Homeland Security and the Treasury

Secret Service l l Protects POTUS, VPOTUS, FORMERS and families Protects visiting foreign heads (FOR DIGS) of state and spouses – l l 4 Can “sign off” – waive their protection In 1997 Clinton said the term of protection should only be for 10 yrs Changed back to for life Forensic Science: Fundamentals & Investigations, Chapter 10

FISH l 5 The Secret Service maintains a handwriting computer data base called the Forensic Information System for Handwriting (FISH). It stores writing samples to use to compare to threat letters received by the USA. Forensic Science: Fundamentals & Investigations, Chapter 10

Forgery-making, adapting or falsifying of documents with the intent of deceiving someone Forged documents can include such things as checks, employment records, legal agreements, licenses, and wills. l Fraudulence is forgery done for material gain. l Check forgery can include: – ordering another’s checks from a deposit slip. – altering a check. – intercepting another’s check, altering, and cashing it. – creating a check from scratch. l 6 Forensic Science: Fundamentals & Investigations, Chapter 10

Prevention of Check Fraud l l l Print checks on chemically sensitive paper Use large font requiring more ink to make alterations more difficult Use high resolution borders on checks Print checks with multiple color patterns Embed fibers that glow under light sources Use chemical wash detection systems that change color when check is altered

Literary Forgery l Documents such as novels, wills or diaries are forged and sold as originals l The best literary forgers aim to duplicate the original document by using materials similar to those used for the original: – old paper – chemically treated materials to fake an older look – inks mixed from substances that would have been used at the time – watermarks that add the appearance of age – tools and styles that would have been popular at the time 8 Forensic Science: Fundamentals & Investigations, Chapter 10

Forensic Linguist 9 § Experts that look at the linguistic content (the way something is written) of a questioned document. § Language that is used can help to establish the writer’s age, gender, ethnicity, level of education, professional training, and ideology. Forensic Science: Fundamentals & Investigations, Chapter 10

Ink Chromatography is a method of physically separating the components of inks Types 10 § HPLC—high-performance liquid chromatography § TLC—thin-layer chromatography § Paper Chromatography Forensic Science: Fundamentals & Investigations, Chapter 10

Paper Chromatography of Ink Two samples of black ink from two different manufacturers have been characterized using paper chromatography. 11 Forensic Science: Fundamentals & Investigations, Chapter 10

Retention Factor (Rf) § § 12 Forensic Science: Fundamentals & Investigations, Chapter 10 A number that represents how far a compound travels in a particular solvent It is determined by measuring the distance the compound traveled and dividing it by the distance the solvent traveled.

International Ink Library The U. S. Secret Service maintains an ink database that includes over 12, 000 inks. Every year ink and pen manufacturers are asked to submit ink formulas to the library. 13 Forensic Science: Fundamentals & Investigations, Chapter 10

Evidence 14 § Class characteristics may include general types of pens, pencils or paper. § Individual characteristics may include unique, individual handwriting characteristics, trash marks from copiers or printers Forensic Science: Fundamentals & Investigations, Chapter 10

Paper Differences § § § § 15 § Raw material Weight Density Thickness Color Watermarks Age Fluorescence Forensic Science: Fundamentals & Investigations, Chapter 10

Pencils Hardness Scale—a traditional measure of the hardness of the "leads” in pencils. l Makes them write differently on paper § The hardness scale, from softer to harder, takes the form. . . , 3 B, 2 B, B, HB, F, H, 2 H, 3 H, 4 H, . . . , with the standard "number 2" pencil being of hardness 2 H. 16 Forensic Science: Fundamentals & Investigations, Chapter 10

Document Alterations § Obliterations - removal of writing by physical or chemical means can be detected by: § § Indentations can be detected by: § § 17 Microscopic examination UV or infrared (IR) light Digital image processing Oblique lighting Electrostatic detection apparatus (ESDA) Forensic Science: Fundamentals & Investigations, Chapter 10

Art Forgeries 18 Forensic Science: Fundamentals & Investigations, Chapter 10

Counterfeiting money is a crime stretching back into ancient times. Items most often forged today include: – – – 19 currency traveler’s checks food stamps certain bonds postage stamps Forensic Science: Fundamentals & Investigations, Chapter 10

Counterfeiting In 1996 the government starting adding new security features to our paper money due to the advanced copying technologies that have raised the incidences of counterfeiting. 20 Forensic Science: Fundamentals & Investigations, Chapter 10

Counterfeit Currency l The Secret Service has worked with electronics and software makers to add security features to paper currency that makes forgery extremely difficult. Scanning cannot reproduce these security features. l The first security feature is the feel of the paper. Regular printer paper contains starch. Paper bills contain rag fiber instead of starch. 21 Forensic Science: Fundamentals & Investigations, Chapter 10