16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An...

13
16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION Chapter 16

Transcript of 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An...

Page 1: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-1

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

DOCUMENT EXAMINATION

Chapter 16

Page 2: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-2

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Introduction• QUESTIONED DOCUMENT:

Any object with handwriting or print whose source or authenticity is in doubt.

• DOCUMENT ANALYSIS: examiners recognize and compare the individual characteristics of questioned/known authentic writings.

• EXEMPLARS: documents of known authorship or origin (known samples taken under the same conditions).

• Handwriting as physical evidence is always individual evidence.

http://www.anomalies-unlimited.com/Death/Cobain/Comparisons.html

Page 3: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-3

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Character of Handwriting• No two individuals write

exactly alike.

• Many factors shape the total character of a person’s handwriting.

• Early stages handwriting - a conscious effort to copy standard letter forms.

• Writing skills improve over time - nerve and motor responses of the brain become subconscious (automatic).

• The natural handwriting of two different individuals can never be identical.

Palmer copybook 1937

Zaner Bloser - 1938

Page 4: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-4

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Character of Handwriting• Variations in angularity, slope,

speed, pressure, letter and word spacing, size ratio of letters, connections, pen movement, writing skill, and finger dexterity.

• Formatting or placement on the paper, such as margins, spacing, crowding, insertions, and alignment.

• Spelling, punctuation, phraseology, and grammar can be personal and help to individualize the writer.

• An individual’s writing style can be altered beyond recognition by the influence of drugs or alcohol.

Anthrax-containing letters

Page 5: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-5

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Character of Handwriting• No one handwriting

characteristic can be taken as the basis for a positive comparison.

• The final conclusion must be based on a sufficient number of common characteristics between the known and questioned writing samples.

• There are no set rules for the number of writing characteristics needed for a match; each case is judged on its own merits.

              

                                                                                                                              

                                                                                                                           

                                                                                                                              

Figure 5. Mickey Mantle's genuine signature is shown top right. The next signature, middle right, is an attempt to imitate Mickey Mantle's signature by means of simulation, which is created by copying an actual model or a mental image of a genuine signature. The third signature, below right, is a traced signature executed by actually following the outline of a genuine signature or overlaying a genuine signature and using transmitted light to follow the line of writing.

Page 6: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-6

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Handwriting Exemplars• Collecting sufficient number

of known writing samples (exemplars) is critical for a handwriting comparison.

• Sample wording should be identical to the questioned document.

• Exemplars should be long enough to show the range of natural variations in a suspect’s writing.

• The writing implement and paper should be the same as the questioned document.

• Dictation of several pages will help to eliminate deception on the part of the suspect.

Page 7: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-7

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Handwriting Analysis• Although not all handwriting

is identifiable to a specific person, handwriting characteristics can indicate or authenticate the origin of a document.

• Age, sex, personality, or intent cannot be determined from handwriting analysis.

• Handwriting comparisons are based on two principles: a) no two people write exactly alike b) distinctive characteristics reoccur throughout every person's writing, although no one writes exactly the same way twice. Lindbergh Baby Kidnapping

Page 8: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-8

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Typewriters and Printing Devices

• Typewriters/printing devices

– Can the make and model of the typewriter/printing devices used to prepare the questioned document can be identified?

– Was a typewriter/printing device the source of the questioned document?

• The individual type style, shape, and size are compared to a complete reference collection of past and present typefaces.

Page 9: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-9

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Machine Characteristics • Any mechanical printing device will result in

wear and damage to the machine’s moving parts. • Wear will be both random and irregular, thereby

imparting individual characteristics to the printing device.

• A document examiner has to deal with computer printers, which often produce typed copies that have only subtle differences (defects).

Page 10: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-10

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Digital Technology• In the cases of photocopiers, fax machines, and

computer printers an examiner may be called on to identify the make and model of a machine or to compare a questioned document with test samples from a suspect machine.

• A side by side comparison is made between the questioned document and the printed exemplars to compare markings produced by the machine.

• Examiners compare transitory defect marks, fax machine headers, toner, toner application methods, and mechanical and printing characteristics.

Page 11: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-11

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Alterations• Document examiners must deal with evidence that has

been changed in several ways, such as through alterations, erasures, and obliterations.

• Erasures by rubber erasers, sandpaper, razor blade or knife to remove writing or typing disturb the fibers of the paper and are readily apparent when examined with a microscope.

• If an alteration is made to a document with ink differing form the original, it can sometimes be detected due to differences in the luminescence properties of the inks.

• Obliteration of writing by overwriting or crossing out to hide the original writing can be revealed by infrared radiation, which may pass through the upper layer of writing while being absorbed by the underlying area.

Page 12: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-12

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein

Other Problems• Infrared photography and reflecting light at different

angles are sometimes successfully used to reveal the contents of a document that has been accidentally or purposely charred in a fire.

• In certain situations, indented writings (partially visible depressions underneath the visible writing) have proved to be valuable evidence.

• It may be possible to determine what was written by the impressions left on a paper pad.

• Applying an electrostatic charge to the surface of a polymer film placed in contact with a questioned document will visualize indented writings.

• A study of the chemical composition of the ink used on documents may verify whether or not known and questioned documents were prepared by the same pen; and the paper itself may be analyzed.

Page 13: 16-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein DOCUMENT EXAMINATION.

16-13

PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458

FORENSIC SCIENCE An IntroductionBy Richard Saferstein