Study Guide w/ Answers

1. What is a question document and how is it analyzed?

- A questioned document is any object containing handwritten or printed material whose source or authenticity is in doubt. It can be analyzed by comparing known handwriting or printed samples (exemplars) with the questioned document, as well as examining the paper, ink, and any potential alterations.

2. What do question document examiners do and how?

- Question document examiners compare handwriting, typewriting, or printing samples, analyze paper and ink, restore altered documents, and identify forged or fraudulent documents. They rely on both requested and non-requested exemplars for comparison..

3. How is handwriting disguised?

- Handwriting can be disguised through inconsistent slant and letter formations, changes in capitals, use of block lettering, major changes in writing size, writing with the wrong hand, and irregular spacing.

4. What is the difference between a request and non-request exemplar?

- A request exemplar is collected under controlled conditions, usually at a police station, where the writer is given specific dictations. A non-request exemplar is obtained from previously written documents under natural conditions.

5. What causes erasures, obliterations, charred, and indented writings and how are they detected?

- Erasures can be caused by abrasives or chemicals, obliterations by overwriting, charred documents by exposure to heat, and indented writings by pressure from writing on top sheets. They are detected using oblique lighting, chemical treatments, or tools like the ESDA (Electrostatic Detection Apparatus).

6. What does an electrostatic detection apparatus (ESDA) do?

- The ESDA highlights indented writing on documents by using a toner to make impressions visible.

7. What do different lighting conditions detect? (VSC)

- The Video Spectral Comparator (VSC) uses ultraviolet through infrared radiation to detect alterations, obliterations, and erasures.

8. What is a stylistic signature?

- A stylistic signature is a personal way of writing a signature, which may not represent typical handwriting but is unique to an individual.

9. When are friction ridges formed?

- Friction ridges form during fetal development, starting in the 9th or 10th week and continuing until about the 17th week of gestation.

10. Where do fingerprints come from, and how are they left behind?

- Fingerprints come from the friction ridges on the hands and feet. They are left behind when the oils and sweat on the ridges are transferred to a surface.

11. What are the different techniques used in processing latent fingerprints? When is each technique used?

- Techniques include fingerprint powders (for smooth, non-porous surfaces), ninhydrin (for porous surfaces like paper), and cyanoacrylate fuming (for non-porous surfaces). Powders are used to create contrast, while chemicals react with amino acids or oils.

12. Know examples of latent, patent, and plastic types of fingerprints.

- Latent prints are invisible and require processing, patent prints are visible with the unaided eye (e.g., in blood or ink), and plastic prints are 3D impressions left in soft materials like clay.

13. How are fingerprints identified? What is IAFIS?

- Fingerprints are identified through the comparison of minutiae points. IAFIS (Integrated Automated Fingerprint Identification System) is a national database for fingerprint identification.

14. Know the different types of ridge patterns (loops, whorls, arches). Be able to identify the different ridge patterns.

- The three main ridge patterns are loops, whorls, and arches. Loops are the most common, followed by whorls, and arches are the least common.

15. What are the levels of the Henry Classification System? What information can be obtained from this?

- The Henry Classification System is used to organize fingerprint patterns. Each finger with a whorl pattern is assigned a numerical value, and the system allows for categorizing and comparing sets of fingerprints.

16. Be able to calculate the Henry Classification System value of a set of fingerprints.

- Each finger with a whorl pattern gets a value, and the sum of these values is used to calculate the Henry Classification System value. This is not simplified or reduced.

17. What is rifling?

- Rifling refers to the spiral grooves cut into the barrel of a firearm that impart spin to a bullet, stabilizing its flight.

18. What is the difference between a handgun and a shotgun?

- Handguns are designed for one-handed use and can be revolvers or semi-automatics. Shotguns are shoulder-fired and can fire multiple projectiles (pellets) or a single slug.

19. How are firearms examined? What is the first thing done?

- Firearms are examined by first ensuring safety, then documenting the firearm, and testing its operation, including firing tests to compare with crime scene evidence.

20. Know facts about toolmark evidence.

- Toolmarks can be individualized based on microscopic striations or impressions left by a tool. Toolmarks result from either perpendicular (impressed) or parallel (striated) contact with a surface.

21. Can toolmark and firearm evidence be unique?

- Yes, toolmark and firearm evidence can be unique due to the microscopic imperfections created during manufacturing and use.

22. What are lands and grooves?

- Lands are the raised portions inside a firearm barrel, while grooves are the indented portions. These features create corresponding striations on a bullet.

23. How is ammunition fired through the barrel?

- When the trigger is pulled, the primer ignites the gunpowder, generating gases that propel the bullet down the barrel. The lands and grooves impart spin, stabilizing the bullet.

24. What type of microscope is used for firearm comparisons?

- A comparison microscope is used to examine and compare bullets and cartridge cases side by side.

25. What elements are in gunshot residue?

- Gunshot residue contains elements such as lead, barium, and antimony.

26. What is the minimum number of characteristics or points that need to be present in impression evidence for an individualization?

- There is no set number of characteristics required, but a sufficient number of unique, corresponding characteristics must be present for an individualization.

27. Know facts about impression evidence.

- Impression evidence involves a donor and a recipient. It can be 2D or 3D, and examples include footwear impressions, tire tracks, and toolmarks.

28. How are searches done for impression evidence?

- Searches for impression evidence may use oblique lighting and physical methods similar to fingerprint detection techniques.

29. What is the difference between 2D and 3D impressions? How are 2D and 3D impression evidence collected and documented?

- 2D impressions are left on hard surfaces like dust, while 3D impressions are left in soft materials like mud. 2D impressions can be lifted, while 3D impressions are cast.

30. How is impression evidence individualized?

- Impression evidence is individualized based on unique characteristics, wear patterns, and microscopic details that set one object apart from others.

31. How are serial numbers restored?

- Serial numbers are restored by polishing the metal surface and applying a chemical solution, which dissolves the altered metal faster than the surrounding metal, revealing the stamped numbers.