Chain of Custody
The Chain of Custody is the paperwork or paper trail (virtual and physical) that documents the order in which physical or electronic evidence is possessed, controlled, transferred, analyzed, and disposed of. Crucial in fields such as law enforcement, legal proceedings, and forensic science, here are several reasons to ensure a proper chain of custody:
1. Preservation of Evidence Integrity
Maintaining an unbroken chain of custody ensures that the integrity of the evidence is preserved. It proves that there hasn’t been any tampering, alteration, or contamination of the evidence during its handling and transfer from one person or location to another.
2. Admissibility in Court
A properly documented chain of custody is necessary for evidence to be admissible in court. It provides assurance to the court that the evidence presented is reliable and has not been compromised, which strengthens the credibility of the evidence and ensures a fair trial.
3. Establishing Accountability
Each individual or entity that comes into contact with the evidence is documented in the chain of custody. This helps track who had possession of the evidence at any given time and ensures transparency and accountability in the evidence handling.
4. Tracking Movement and Location
The chain of custody documents the movement and location of evidence from the time of collection until its presentation in court or disposition. Investigators, attorneys, and other stakeholders must be able to track the progress of the case and ensure that all necessary procedures are followed to the letter.
5. Protecting Against Contamination or Loss
Properly documenting the chain of custody helps prevent contamination or loss of evidence. By recording each transfer and handling the evidence, any discrepancies or irregularities can be identified and addressed promptly, minimizing the risk of compromising the evidence.
6. Ensuring Compliance with Legal Requirements
Many jurisdictions have specific legal requirements regarding the documentation and maintenance of the chain of custody for different types of evidence. Adhering to these requirements is essential to ensure that the evidence is legally admissible and that all necessary procedures are followed.
Maintaining the chain of custody involves the following typical steps:
1. Collection
One cannot understate the use of proper techniques and tools to avoid contaminating or damaging the evidence when collecting evidence from the crime scene or other relevant locations.
2. Documentation
Immediately after collection, the person collecting the evidence must document details such as the date, time, location, description of the evidence, and the names of those involved in the evidence collection. The CSI Linux investigation platform includes templates to help maintain the chain of custody.
3. Packaging and Sealing
The evidence must be properly packaged and sealed in containers or evidence bags to prevent tampering, contamination, or loss during transportation and storage. Each package should be labeled with unique identifiers and sealed with evidence tape or similar security measures.
4. Labeling
Each package or container should be labeled with identifying information, including the case number, item number, description of the evidence, and the initials or signature of the person who collected it.
5. Transfer
Whenever the evidence is transferred from one person or location to another, whether it’s from the crime scene to the laboratory or between different stakeholders in the investigation, the transfer must be documented. This includes recording the date, time, location, and the names of the individuals involved in the transfer.
6. Receipt and Acknowledgment
The recipient of the evidence must acknowledge receipt by signing a chain of custody form or evidence log. This serves as confirmation that the evidence was received intact and/or in the condition described.
7. Storage and Security
The evidence must be stored securely in designated storage facilities that are accessible only to authorized personnel, and physical security measures (e.g., locks, cameras, and alarms) should be in place to prevent unauthorized access.
8. Analysis and Testing
Any analysis or testing should be performed by qualified forensic experts following established procedures and protocols. The chain of custody documentation must accompany the evidence throughout the analysis process.
9. Documentation of Analysis Results
The results of analysis and testing conducted on the evidence must be documented along with the chain of custody information. This includes changes in the condition of the evidence or additional handling that occurred during analysis.
10. Court Presentation
If the evidence is presented in court, provide the chain of custody documentation to establish authenticity, integrity, and reliability. This could involve individual testimony from those involved in the chain of custody.
You can learn more about the proper chain of custody in the course “CSI Linux Certified Computer Forensic Investigator.” All CSI Linux courses are located here: https://csilinux.com/academy/
Here are some other publicly available resources about the importance of maintaining rigor in the chain of custody:
· CISA Insights: Chain of Custody and Critical Infrastructure Systems
This resource defines chain of custody and highlights the possible consequences and risks that can arise from a broken chain of custody.
· NCBI Bookshelf – Chain of Custody
This resource explains that the chain of custody is essential for evidence to be admissible in court and must document every transfer and handling to prevent tampering.
· InfoSec Resources – Computer Forensics: Chain of Custody
This source discusses the process, considerations, and steps involved in establishing and preserving the chain of custody for digital evidence.
· LHH – How to Document Your Chain of Custody and Why It’s Important
LHH’s resource emphasizes the importance of documentation and key details that should be included in a chain of custody document, such as date/time of collection, location, names involved, and method of capture.
Best wishes in your chain of custody journey!
