Maintaining Chain of Custody in Digital Forensics: What You Should Know
When evidence is collected for a digital forensics case, a chain of custody must be established. If any step in the chain of custody process is missed, there is a risk that electronic evidence presented to the courts could be considered inadmissible. To protect your case’s evidence, you will want to work with digital forensics experts who understand the proper procedures for collecting and transferring evidence so that it remains legitimate and can stand in court.
To help you understand the importance of the chain of custody in digital forensics, we explain what it is, how it is established, and how it can be preserved.
What Is the Chain of Custody?
The chain of custody is the paper trail or chronological documentation of digital evidence. It establishes the sequence of control and the process for collecting, transferring, and analyzing the data in question. It keeps a record of every person who handled the evidence, the dates and times the data was collected or transferred, and the purpose for the transfer. If any information is missing from the chain of custody, the evidence could become inadmissible in court.
Why Is It Important to Maintain a Chain of Custody in Digital Forensics?
When conducting a criminal investigation, digital evidence is key to convicting the guilty parties and gaining restitution. If a chain of custody is not established, the entire case could be jeopardized.
Establishing a chain of custody can make a digital forensics examiner’s job easier. It may reveal useful information such as where the evidence originated, who handled it, and what equipment it was used on.
The court will examine the chain of custody to ensure the electronic evidence is legitimate and has not been tampered with. If there’s a missing link in the chain of custody, the court can overturn the evidence. You could lose crucial evidence simply because a chain of custody was not properly established.
What Is the Chain of Custody Process?
To ensure the digital evidence is not compromised, the chain of custody should begin from the initial point of data collection and continue through the time of presentation to the Courts. Here’s an overview of the four stages of the chain of custody:
- Data Collection: The chain of custody process is begun as soon as data is collected. The forensic examiner will identify, label, and record the digital evidence, including information such as how it was collected, where it was stored, and who has access to it.
- Examination: During this stage, the forensic process used is outlined in the chain of custody. The examiner will include screenshots of the process to show which tasks were completed and the evidence recovered.
- Analysis: In the Analysis stage, the digital forensics specialists will use forensic methods and techniques to discover useful information for the case in question.
- Reporting: Finally, everything from the Examination and Analysis stages must be documented. Reporting includes writing a statement regarding the chain of custody, explaining the tools used during discovery, identifying issues, and more.
How Can You Preserve the Chain of Custody?
Digital forensic specialists follow a few best practices to preserve the integrity of the chain of custody. These principles include:
- Do Not Work on the Original Materials: When handling digital evidence, you should always make a copy to work on so that the original isn’t damaged. You will want to be able to compare the modified version to the original evidence to ensure there aren’t any discrepancies.
- Take Photos and Screenshots of the Evidence: Taking photos of electronics and screenshots of digital evidence establishes the chain of custody.
- Record the Date and Time of Receipt: Documenting timestamps of evidence allows forensic analysts to establish a timeline of where the data has been.
- Create a Digital Forensic Image and Authenticate It: The image will be a bit-for-bit clone of the original evidence uploaded to the forensic computer for investigation. Once the image is uploaded, it must be authenticated using a hash analysis.
Cornerstone Discovery Can Help You Establish a Chain of Custody
Ensure your digital investigation goes smoothly by partnering with Cornerstone Discovery. Our digital evidence specialists rigorously follow all the best practices and procedures for establishing a chain of custody. You can rest assured that we will log crucial information from the moment the digital devices are seized to the conclusion of the matter. Contact us today to speak with our digital forensic examiners.