Section 5.4: Firearms and Toolmarks

When it comes to handling firearms in forensic investigations, the approach is meticulous, ensuring every piece of potential evidence is preserved properly. From the moment a firearm is found, it’s handled with extreme care to prevent any alteration to its state, particularly to avoid disturbing fingerprints or other trace evidence like gunshot residue.

The very first step is making sure the firearm is safe and unloaded. This is critical, both for the safety of the individuals handling the evidence and to maintain the integrity of the firearm as evidence. In cases where there’s uncertainty about safely handling or unloading a firearm, experts are consulted to prevent any accidents or damage to the evidence.

Documentation plays a crucial role in the process. The firearm is photographed meticulously, including a scale for size reference and an identification label to ensure every detail is captured accurately. If the firearm lacks a serial number or it’s been tampered with, additional marking is applied for identification purposes.

Special attention is given to the packaging of firearms, revolvers, and their ammunition. Each item is marked clearly and documented, including details such as the serial number, make, model, caliber, and the condition of the firearm, such as the presence of any stains or the number of rounds in the chamber. This detailed approach not only aids in the analysis by firearms examiners but also ensures the evidence is robust enough to stand up to legal scrutiny.

Following strict protocols, including those set by departmental and U.S. Department of Transportation regulations, is essential for the shipment of firearms and ammunition. The use of rigid containers, evidence tape seals, and detailed documentation underscores the thoroughness required in forensic firearms analysis, highlighting the importance of preserving trace evidence and maintaining the evidence chain of custody throughout the investigative and legal process.

🔍 Reflect

Considering the detailed steps taken from collecting to packaging firearms for forensic analysis, why do you think each step is critical for preserving the evidence? How might any oversight in this process affect the investigation and the evidence’s credibility in court?

Handling Firearms for Evidence

Preparing the Firearm

When it comes to packaging firearms for forensic analysis, careful handling is key. First off, all firearms should be made safe and unloaded. If you’re not sure how to handle a firearm safely, always ask for help from someone who knows, like a firearms instructor. It’s crucial to follow all safety guidelines to the letter.

Documenting the Firearm

Documenting the firearm thoroughly is next on the list. Taking clear photographs with a scale and an ID tag is essential. These photos should show all details of the firearm, including any serial numbers, stains, or the position of the safety catch. If a firearm lacks a serial number because it’s old or has been tampered with, you’ll need to mark it yourself with important details like your initials and the date.

Labeling and Packaging

Every firearm needs a unique evidence number, and this should be clearly labeled on the firearm’s packaging. The label should include:

• The type of firearm.
• The location of any stains (noting if they’re wet or dry).
• The location where the firearm was found.

Before packaging the firearm, it’s important to label the container properly and seal it right away. This step helps protect the evidence and ensures it remains unchanged from the scene to the lab.

Handling with Care

When moving the firearm, avoid touching any smooth surfaces where fingerprints might be found. Instead, hold it by any textured parts like the grip. This helps preserve any latent prints that could be crucial evidence.

🔍 Reflect

Considering the delicate nature of firearm evidence, why do you think such meticulous steps are necessary during the collection and packaging process? How might these procedures impact the analysis of the evidence and the outcome of a case?

Understanding Different Firearms

Firearms come in many shapes and sizes, each requiring specific documentation and handling procedures. The initial step in processing any firearm as evidence involves a thorough documentation of its unique markings, including the serial number, make, model, and caliber. If a serial number is absent, it’s essential to mark the firearm with identifying data, ensuring traceability throughout the investigation process.

Key Documentation Details

For all firearms, certain critical details must be noted:

• The position of the safety mechanism (on or off)
• The presence of ammunition within the chamber
• Specifics about any stains found on the firearm
• Serial number, make, model, and caliber or gauge of the firearm

Safe Handling Practices

Ensuring the firearm is unloaded and secured is paramount for the safety of all involved. If there’s any uncertainty about safe handling practices, it’s advisable to consult with a firearms expert. When removing ammunition for documentation, each piece should be individually marked and cataloged, detailing its specific chamber or magazine position and the type of projectile it contains.

Packaging Firearms and Ammunition

Special care should be taken to protect the firearm’s integral parts, like the barrel and chamber, from damage. The firearm and its ammunition should be placed in designated containers, labeled with all pertinent details for easy identification. Any removable magazines should also be marked to correlate with the ammunition they contain.

Final Steps in Evidence Collection

Once all components are securely packaged, sealing the container with evidence tape and adding identification details finalizes the process, maintaining the integrity of the chain of custody. This careful approach ensures that all potential evidence, including latent fingerprints and trace evidence, is preserved for forensic analysis.

🔍 Reflect

Considering the detailed steps required for handling and documenting various firearms, why is such precision necessary in forensic investigations, and how do these procedures aid in ensuring the reliability of evidence analysis?

Handling Embedded Ammunition in Evidence

Collecting Fragile Evidence

The collection of gunshot residue and fingerprints is a delicate task. These types of evidence are highly sensitive and should be collected promptly to avoid any loss or contamination. If the ammunition is embedded within an object, efforts should be made to collect the entire object, if feasible, to preserve the evidence’s context.

Safety and Documentation

Safety precautions are paramount when handling objects that may cause injury. Additionally, thorough documentation of the object and the embedded ammunition is essential. This includes taking detailed photographs with a scale and an identification label, noting the object’s location, and documenting its relationship to other evidence at the scene. Techniques such as using rods or strings can help illustrate the trajectory of the ammunition through entry and exit points.

Detailed Observation

In your documentation, include:

• The location of the embedded ammunition within the object
• The type of ammunition, if identifiable
• The apparent entry angle of the ammunition

Extraction Techniques

When extracting the embedded ammunition, use tools like hammers, chisels, or forceps with care. It’s vital to avoid damaging the ammunition or altering any marks on it, which could be critical for ballistic analysis. Collecting additional fragments or related items is also crucial, as these may provide further evidence.

Packaging and Labeling

Every piece of evidence, including the object containing the embedded ammunition, must be properly labeled with your initials, identification number, evidence number, and a detailed description. This information should reflect the unique nature of the evidence and its context within the investigation.

• Evidence description might include the type of object, its color, the type of ammunition (if known), and the ammunition’s specific location within the object, detailed with orientation to significant features of the scene.

After collecting, place the object in a properly labeled container, secure it with evidence tape, and mark it with your identification details and the date and time. This process ensures the integrity of the evidence and maintains the chain of custody.

🔍 Reflect

Considering the meticulous process involved in handling and documenting embedded ammunition, why is each step crucial for maintaining the integrity of forensic evidence, and how does this thoroughness impact the overall investigation?

Collecting Fired Casings and Wads

The Importance of Preservation

Collecting fired casings and wads from a crime scene requires careful handling to preserve potential fingerprints and other trace evidence. The process starts with the preparation of bindles using a “druggist fold,” ensuring that these small but crucial pieces of evidence are securely contained. Wearing clean gloves during this process is essential to prevent contamination.

Documentation and Photography

Documenting the scene and the specific location of each casing or wad is a critical step. This includes taking photographs with a scale and an identification label to provide a clear record of where each piece was found and its relationship to other evidence at the scene.

Labeling and Packaging

Each casing or wad, as well as its packaging container, must be labeled with specific details such as your initials, identification number, the date and time, and a unique evidence number. This meticulous labeling ensures a robust chain of custody and aids in the analysis phase. The description should detail the type of casing or wad, the suspected weapon used, and the exact location where it was found.

When collecting, carefully pick up each piece to avoid altering any evidence it may carry. If the item is embedded or difficult to access, use appropriate tools to retrieve it gently. For organization and analysis purposes, each casing or wad should be placed in its own labeled container, especially if multiple items are collected from the same area.

Special Considerations for Wads

Wads, which can carry unique evidence regarding the firearm used, should not be packaged with other types of ammunition or objects to prevent cross-contamination. Each item’s container should be sealed with evidence tape, and all identifying information should be marked across the seal to maintain the integrity of the evidence.

🔍 Reflect

Considering the detailed process of collecting, documenting, and packaging fired casings and wads, why is meticulous attention to detail crucial in forensic investigations, and how do these efforts contribute to the accuracy and reliability of the evidence analysis?

Handling Loose Unfired Ammunition

Documenting the Scene

When encountering loose unfired ammunition at a crime scene, the first step is thorough documentation. This includes taking detailed photographs of each piece of ammunition and its surroundings. Ensure each photo includes a scale and an identification label to provide context on the size and importance of the ammunition within the investigation.

Labeling for Analysis

Before collecting any ammunition, prepare an envelope for each piece, labeled with crucial information such as your initials, identification number, the date and time, and a unique evidence number. This approach guarantees a robust chain of custody from the scene to the forensic laboratory. The description on each label should detail:

• The type of ammunition.
• Its precise location at the scene.
• Its orientation in relation to a firearm or other points of interest, if applicable.

Collection and Preservation

Carefully collect the ammunition to preserve potential fingerprints or other trace evidence. It’s essential not to wrap the ammunition in additional materials before placing it in the labeled envelope, as this could compromise the evidence.

Packaging and Transport

Once collected, securely seal the envelope with evidence tape, noting your initials and the date and time across the seal to ensure the evidence’s integrity. If multiple pieces of ammunition are found, each should be placed in its own container and labeled accordingly. These containers can then be grouped for transport, maintaining order and preventing contamination between samples.

🔍 Reflect

Given the precise steps required to collect, document, and package loose unfired ammunition, why is it important to follow these guidelines carefully, and how does this process contribute to the integrity and usefulness of the ammunition as evidence in an investigation?

Handling Tool Mark Evidence

Understanding Tool Marks

Tool marks include any impressions, scratches, or abrasions made by a tool on an object. These marks can be crucial in investigations, sometimes linking a tool to a person involved in a crime. Capturing the detail of these marks is essential for forensic analysis.

Documentation and Collection

Start by photographing the object with the tool mark to establish its context within the scene. Then, focus on capturing detailed shots of the mark itself. Since tool marks are three-dimensional, photos alone can’t be used for examinations, but they play a critical role in documenting the evidence.

Comparing Tool Marks

The most effective method for comparing tool marks involves submitting the item with the mark and the suspected tool to a forensic lab. To preserve the tool’s condition, wrap its working area in paper and avoid inserting it into the mark to prevent damage.

Dealing with Non-removable Marks

If the marked object is too large or cannot be submitted to a lab, consider creating a silicone cast of the tool mark. Silicone captures fine details well, making it ideal for forensic examination. Avoid using materials like Plaster of Paris, which may not capture the necessary detail.

Making a Silicone Cast

When creating a cast, follow the silicone kit’s instructions carefully. You can incorporate an identification tag into the silicone’s edge, ensuring it doesn’t affect the cast’s detail. Always wear clean gloves to prevent contaminating the evidence.

Labeling and Packaging

Label a container for the cast with all necessary identification data. Be meticulous in documenting the cast’s type, location, and orientation, ensuring each piece of evidence is uniquely numbered and matches the scene’s documentation. Package the item carefully, sealing the container with evidence tape and marking it with all pertinent details.

Final Steps

Ensure loose materials are cleared from the impression without altering it. All casts, regardless of their condition upon removal, should be submitted for analysis. Keep the suspect tool(s) separate from the item with the tool mark to avoid additional damage.

🔍 Reflect

Considering the intricate process of handling tool mark evidence, from documentation to casting, what does this meticulous approach tell you about the challenges and precision required in forensic investigations? How does each step contribute to preserving the evidence’s integrity for analysis?

Summary and Conclusions

• Stevens, B. L. (2017).  Comprehensive Modernization of Firearm Discharge Residue Analysis: Advanced Analytical Techniques, Complexing Agents, and Tandem Mass Spectrometry.  

Modification History

File Created:  05/02/2019

Last Modified:  04/09/2024

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This work is licensed under an Open Educational Resource-Quality Master Source (OER-QMS) License.