Tool Marks Objective Sheet

Chapter 17: Tool Marks

Student Learning Objectives

Forensic Science: Fundamentals and Investigations, 2nd ed., Bertino & Bertino, 2015

At the conclusion of this chapter, the student should be able to:

General Information on Tool Marks

_____ 1. Discuss the significance of tool marks in criminal investigations.

_____2. List three major types of tool marks.

_____ 3. Distinguish between an abrasion mark, a cutting mark, and an indentation mark.

_____4. Prepare a chart comparing abrasions, cutting marks and indentation marks.

Include in the chart:

a. how the mark was formed

b. examples of tools that would make that mark

c. description of the type of tool mark

_____ 5. Describe the type of crime scenes were tool marks are commonly found.

_____ 6. Explain why ownership of a tool consistent with tool marks from a crime scene is considered to be circumstantial evidence.

_____ 7. List factors that could individualize a tool.

_____ 8. List examples of trace evidence that can be found in a tool mark that could help solve a crime.

_____ 9. Explain how tools mass-produced by the same manufacturer can be distinguished from each other.

_____10. Describe how serial numbers on tools can link a suspect to a particular tool.

Indentation Marks

_____ 11. List examples of tools that commonly leave marks at a crime scene.

_____12. Explain the relationship between the softness of the material and the depth of the mark made by a tool.

_____13. Explain how a negative impression of a tool is formed.

_____ 14.Describe what type of information can be gained by examination of a negative impression of a tool.

_____15. How can oxidation (rusting) of a tool be used to link a suspect's tool to a tool mark at a crime scene.

Abrasion and Cutting Marks

_____ 16. List several types of tools that are likely to leave abrasion marks.

_____ 17. List several examples of tools that are likely to leave cutting marks.

_____ 18. Compare and contrast the different cutting marks produced by different type of saws.

_____ 19. Describe what type of information can be learned by the examination of cutting mark on bones.

_____20. Discuss the forensic importance of the database of saw and knife marks at the C.A. Pound Human Identification Laboratory at the University of Florida.

Photographing Tool-Mark Evidence

_____21. Discuss how to best photograph tool marks. Include in your answer:

a. when to photograph the evidence

b. what should be included in the photograph

c .what type of lighting provides better images

d. what the camerashould focus on when taking the image

Casting Impressions of Tool Marks

_____22. Explain why removing the tool mark from the crime scene is advantageous to creating a duplicatemark.

_____ 23. Provide arguments for never placing a suspect's tool directly into the crime-scene tool mark.

_____24. Explain the importance of documenting and photographing tool marks prior to casting an impression.

_____ 25. Explain the importance of documenting,examining, and collecting any trace evidence from the impression prior to casting an impression.

_____ 26. Describe the procedure of casting an impression of a tool.

_____27. Describe different casting materials that can be used to cast impressions.

_____28. Elaborate on why sample impressions are made from a suspect's tool when comparing tool marks at the crime scene with tool marks made from a suspect's tool(s).

_____29. Describe the role of the comparison microscope in analyzing tool marks.

Evidence Collection

_____ 30. Discuss how to properly collect and package tools and or tool -mark evidence so that no evidence is lost or damaged.

_____ 31. Describe what type of information needs to be written on a tool-mark evidence package.

_____ 32.Describe other types of evidence that should be photographed, documented, and collected from tools used at a crime scene. Include in your answer:

a. paint

b. human tissues such as hair and bone

c. clothing and fibers

d. blood

e. oils, grease

f. soil, dust

g. rust

_____ 33. Discuss advances in technology that are improving the ability to compare tool marks. Include in your answer:

a. tool-mark databases

b. development of algorithms to statistically analyze evidence

b. profilometers

_____34. Properly sequence the order of events when documenting tool-mark evidence:

a. photographing

b. collecting fingerprints from the tool

c. preparing a sketch of the tool mark and or tool

d. casting the impression

removing other evidence from tool or tool mark
preparing a written description of the tool or tool mark

g. measuring the impression

_____35. Discuss measures being taken by the Scientific Working Groupsand theOrganization of Scientific Area Committees(OSAC) in improving the reliability of tool-mark evidence.