CRI023: Forensic Chemistry and INSTRUCTOR:

Toxicology Ma’am Jheanly Vivien Alberca

Laboratory #15: Tool Marks DATE: Sep 19, 2024
Group number: _____ SCORE:
Names:

Boborol, Wengky M.
Payla, Jaymark F.
Alim Janreeve
Macadi, Anwar
Ruita, Sheann
Elymario, Amora L.
Bonjovie, Lagamao P.
Carl Justin, Gerong
Balahay
Cogal

Objectives: At the end of the module, students will be able to:

1. explain how the procedure of tool mark investigation,
2. discuss the uses of tool marks and its importance, and
3. examine tool marks.

Materials:
 Pliers
 Hammer
 Scissors
 Chasel
 2 Wood block (2inx2inx4ft)
 Camera

Activity #1 Tool Marking

Directions: Perform the procedure and write your observations on the tool markings with
a given angle depending on your gender.

Procedure:

1. Steady a wooden block upright.

2. With a male in your group, hit it strong three times with a tool. For the wrench or
pliers, grip it tightly on it. High, Low and Mid angle.
3. Make sure to take great caution while doing the experiment. Also to isolate the
strikes in one place on the wood.
4. Take pictures of strikes done by the tool.
5. Repeat the steps 1 to 3 for all the tools.
6. Repeat the procedure with a female classmate doing the strikes.
 Table 1. Observation of the Tool Marking perform male representative
Tools Gender
Male
High Angle Mid Angle Low Angle
Hammer At a high angle, the Striking the wood at a mid At a low angle, the force
force is concentrated, angle distributes the force is spread over a larger
causing deeper evenly, reducing deep area, causing minimal
penetration, more penetration and severe penetration and surface
rebound, and a sharper, damage, producing a damage, with minimal
louder sound. moderate sound, rebound and a softer
sound.
Pliers At a high angle, the At a mid angle, the marks At a low angle, the impact
impact created deep were moderately deep and resulted in shallow marks
indentations and spread out, with better and minimal splintering,
significant splintering, control and less intense with the pliers having
with the pliers rebound. minimal rebound,
rebounding forcefully, providing the highest
making control difficult level of control and
safety.
Star At a high angle, the At a mid angle, the tool At a low angle, the tool
Skrew impact tends to create mark is more elongated mark is shallower and
deeper, more and less deep, with wider, causing a
pronounced indentations smoother edges and less superficial indentation
with sharper edges, as splintering due to even with minimal splintering,
the force is concentrated force distribution. resembling a scrape or
over a smaller area. abrasion.
Ice pick At a high angle, the ice At a mid angle, the tool low angle, the tool mark
pick creates deep, mark is more elongated is shallower and wider,
narrow punctures with and less deep compared to with the force spread over
sharp edges, penetrating a high angle strike. The a larger area. This results
the wood significantly edges of the mark are in a more superficial
and often causing smoother indentation with minimal
splintering around the splintering, and the mark
entry point. may appear more like a
scrape or abrasion rather
than a deep puncture.
 Table 2. Observation of the Tool Marking perform by female representative
Tools Gender
Female
High Angle Mid Angle Low Angle
Hammer At a high angle, the When the hammer is used The low angle creates
hammer creates deep, at a mid angle the impact precise, less pronounced
pronounced indentations force is balanced, indentations, ideal for fine
and irregular tool marks, producing clear, control, making it easier
making it easier to consistent indentations to observe the impact
identify the strike’s without excessive point and strike direction.
direction and force. splintering.
Pliers When a female struck a At a mid angle, the marks At a low angle, the impact
wooden surface with were shallower and more was distributed over a
pliers at a high angle, the spread out, with moderate larger area, resulting in
impact was concentrated, splintering and better tool shallow marks and
causing deeper control. The rebound was minimal splintering.
indentations and less intense, resulting in a
pronounced splintering. more stable and accurate
strike.
Stars At a high angle, the At a mid angle, the tool At a low angle, the tool
Skrew impact tends to create mark is more elongated mark is shallower and
deep, sharp indentations and shallow, with wider, resulting in a
with pronounced edges, smoother edges and less superficial indentation
similar to those observed splintering due to even with minimal splintering.
in male participants. force distribution. The mark may resemble a
scrape or abrasion.
Ice pick At a high angle, typically At a mid angle, tool At a low angle, the ice
close to 90 degrees, the marks are elongated and pick creates shallow,
ice pick will create deep, oval-shaped with elongated marks with
circular puncture marks noticeable striations, pronounced striations and
with minimal lateral combining penetration noticeable lateral
striations. and scraping to create a scraping, indicating the
distinct pattern. force’s direction.

Table 1 and 2. show’s the researchers observation to the tool marking experiment.
The experiment underscored the importance of attention to detail and the ability to
discern subtle differences, which are crucial in linking a tool to a crime scene. Overall,
the observation highlighted the intricate relationship between the tool and the marks it
leaves, reinforcing the significance of tool mark analysis in forensic investigations.
Questions:

1. Why is it important to identify if a tool mark hits a victim or an object from

high,low or mid angles? Elaborate.

Identifying the angle of a tool mark is crucial in forensic investigations as it

reveals the dynamics of the crime, including the positions and movements of the
perpetrator and victim. High-angle marks suggest the attacker was above the victim,
while low-angle marks indicate crouching or a prone victim. This information helps
corroborate witness statements and suspect alibis, identify the specific tool used, and
assess the force applied. Accurate interpretation of tool marks aids in determining the
nature of wounds and provides compelling evidence in court.

2. Why is it important to know the shallowness or depth of strikes made by a

tool mark? Elaborate.

Understanding the shallowness or depth of strikes made by a tool mark is vital in

forensic investigations because it provides critical information about the force and
manner of the attack. The depth of a tool mark can indicate the amount of force applied
during the strike, which helps forensic experts assess the severity of the incident and the
potential intent of the perpetrator. Deeper marks often suggest a more forceful impact,
possibly indicating a higher level of aggression or intent to cause significant harm.
Shallower marks suggest less forceful strikes, possibly defensive or accidental. The depth
helps identify the tool used, link suspects to the crime scene, and reconstruct events,
providing crucial evidence for justice.

3. What are the difficulties you encountered during the experiment?

During the experiment, several difficulties were encountered that impacted the
overall process and outcomes. One major challenge was maintaining consistent
environmental conditions, as fluctuations in temperature and humidity could affect the
accuracy of the measurements and the behavior of the materials being tested. Additionally,
there were issues with the calibration of the equipment, which required frequent
adjustments and recalibrations to ensure precise readings. Communication and
coordination among team members also posed challenges, especially when integrating
findings from different parts of the experiment.

4. If you will find the same tool markings on a body, how would the markings
help you in investigating the crime?

Finding the same tool markings on a body can be crucial in a criminal

investigation. These markings can help forensic experts determine the type of tool used,
which can then be linked to a specific suspect or crime scene. By analyzing the unique
patterns and characteristics of the tool marks, investigators can identify the tool’s make
and model, and sometimes even the specific tool itself if it has distinctive wear or damage.
This information can be used to establish a connection between the suspect and the crime,
especially if the tool is found in the suspect’s possession or at their residence.

Additionally, tool markings can provide insights into the manner and sequence of
the crime, helping to reconstruct the events leading up to the victim’s injuries. Overall,
tool mark analysis is a valuable method in forensic science for linking evidence to
suspects and understanding the dynamics of the crime.
Documentations:

Image 1. Tool marked of hammer performed Image 2. Tool marked of hammer performed
by male representative by female representative

Image 3. Tool marked of Plair performed by Image 4. Tool marked of Plair performed by
male representative female representative

Image 5. Tool marked of star skrew Image 6. Tool marked of star skrew
performed by male representative performed by female representative

Image 7. Tool marked of ice pick performed Image 8. Tool marked of ice pick performed
by male representative by female representative
 Image 10. pliers, grip it tightly on it. High, Low
and Mid angle.
Image 9. Preparation of tools and
material needs.

Image 11. use force to hit the wood Image 12. use force to hit the wood
using ice pick using star skrew