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  • Writer's pictureSigurður Ragnarsson

The Indispensable Role of Digital Forensics in Combating Illegal Image and Video Crimes



 

When it comes to online abuse, the importance of digital forensics cannot be overstated. The scourge of online abuse, particularly through the misuse of images and videos, presents a daunting challenge. Digital forensics is pivotal in this battle, offering rescue and justice for victims of image-  and video-based abuse.  


Here, we aim to provide an in-depth exploration of digital forensics, emphasizing its indispensable role in detecting, analyzing, and combating the illegal distribution of images and videos. As these issues become more prevalent in our interconnected world, understanding the nuances of digital forensics is crucial for professionals tasked with safeguarding digital integrity and confronting online abuse. 


Understanding digital forensics


Digital forensics is the practice of uncovering and interpreting electronic data. The goal is to preserve any evidence in its most original form while performing a structured investigation by collecting, identifying, and validating the digital information for the purpose of reconstructing past events. This field is essential for solving crimes in the digital space, ranging from data theft to the distribution of illegal content.


Why digital forensics is essential in the fight against illegal imagery 


Digital forensics plays a pivotal role in modern investigations. It's not just about recovering deleted files or tracing the source of a cyberattack; it's about bringing to light the invisible crimes that happen in the digital shadows. In cases of illegal image and video distribution, experts work to trace the source, identify the perpetrators, and help deliver justice for the victims.


How investigations address sextortion, CSAM, and other forms of digital abuse


Digital forensics stands at the forefront of tackling some of the most challenging and distressing aspects of cybercrime, including sextortion, the distribution of Child Sexual Abuse Material (CSAM), and ensuring trust and safety on digital platforms.


In cases of sextortion, where victims are coerced into complying with demands under the threat of releasing private sexual images or videos, digital forensics experts play a pivotal role. They utilize their skills to trace the digital communication lines, often shrouded in layers of anonymity, to pinpoint the source of these threats. This not only involves analyzing emails and social media messages but also involves preserving these communications in a legally admissible format, which is crucial for subsequent prosecution.


Tackling the web’s most repulsive crime 


When it comes to the abhorrent crime of distributing CSAM, digital forensics takes on an even more critical role. Experts employ sophisticated tools that go beyond simple detection; they analyze the distribution networks, applying hashing algorithms to identify known illegal images and videos. This level of analysis is not just about finding the material but understanding how it circulates, which is key in dismantling the networks involved in such heinous crimes.


Enhancing trust and safety


In the realm of online platforms, the role of digital forensics in maintaining trust and safety is becoming more prominent as the online technologies advance. Here, the focus shifts to content moderation and policy enforcement. Digital forensic experts assist in identifying and removing illegal or harmful content. This task is particularly challenging given the vast amount of user-generated content and the constantly evolving nature of digital communication. By analyzing trends and tactics used by offenders, these experts enable platforms to adapt and enforce their policies more effectively, thereby protecting users from digital abuse and maintaining a safe online environment.




Common investigative procedures


Digital forensics procedures are meticulously designed to handle the sensitive and often complex nature of crimes involving illegal imagery and video content. The process encompasses four fundamental stages, each critical to the integrity and success of the investigation.


1. Preservation: Securing evidence


When dealing with illegal images and videos, preserving the evidence entails more than just securing the physical device. It involves safeguarding the digital data in a way that prevents its alteration or deletion, which is especially challenging given the often volatile nature of digital media and the sophisticated methods used by criminals to conceal their activities.


This stage includes creating forensic images of storage devices, securing network logs, and safeguarding cloud storage accounts. Special care is taken to maintain the chain of custody, ensuring that the evidence is admissible in court. Tools like write blockers are used to prevent any changes to the original data.


2. Collection: Ensuring the integrity of evidence


The collection phase in cases of illegal content requires careful strategizing to capture relevant data without violating privacy norms or legal boundaries. This involves using specialized software to scan devices and networks for specific types of files, such as images and videos, and using hash values to identify known illegal content.

Ensuring the integrity of the collected data is paramount. This includes documenting the exact methods of collection and using cryptographic hashes to verify that the data has not been altered from the time of collection to its presentation in court.


3. Examination and analysis


In this stage, experts employ advanced techniques to analyze the content of images and videos. This can include the examination of file metadata, frame-by-frame analysis of videos, and the use of machine learning algorithms to identify and categorize illegal content.


The analysis also extends to uncovering the context around the creation and distribution of the content. This can involve tracing the digital footprints left by the devices used to capture or share the content, and even recovering deleted files that may provide additional evidence.



Apprehension of hardware and devices

Before seizing any hardware, digital forensics investigators ensure they have the necessary legal authorization, such as warrants, which are crucial for the admissibility of evidence in court.


Next, the physical collection of devices is done with extreme care to avoid any damage or alteration of data. This can include computers, smartphones, external storage devices, and any other digital storage mediums. Maintaining a strict chain of custody throughout this process is paramount. This involves documenting every individual who handles the evidence and any actions taken with it, thereby preserving its integrity for legal proceedings.


Techniques for tracing content


Once the devices are secured, investigators use a range of techniques to trace and analyze the content, including: 


  1. Initial assessment: A preliminary assessment of the device is conducted to determine the best approach for extraction and analysis, considering factors like the device’s make, model, and condition.

  2. Data duplication: Before any analysis, an exact copy of the data is created using write-blocking tools to ensure the original data remains unaltered. This duplicate data is what investigators work on.

  3. File system analysis: Investigators examine the file system for hidden, deleted, or encrypted files. Advanced software is used to recover files that the perpetrator may have attempted to destroy.

  4. Metadata examination: Metadata within files, such as creation dates, modification dates, and geolocation data, can provide critical insights into the origins and history of the files.

  5. Internet history and cache analysis: Investigating the device’s internet history and cache can reveal downloaded content or websites visited by the user, which might be pertinent to the investigation.

  6. Keyword searches and hash matching: Automated tools perform keyword searches for relevant terms. Additionally, hash matching is used to identify known illegal images or videos against databases like the National Center for Missing & Exploited Children’s (NCMEC) hash list.

  7. Network analysis: In cases where content was shared or received online, investigators may analyze network logs to trace the movement of the content across networks.





The importance of cross-media tracing: Find image from video and vice versa



In the realm of digital forensics, particularly when dealing with illegal imagery and videos, the ability to trace an image or single frame against a video and vice versa is of paramount importance. This cross-media tracing plays a crucial role in comprehensive investigations, offering a broader and more accurate understanding of the evidence at hand.


Uncovering linked evidence


Often, digital evidence does not exist in isolation. An image may be a still from a video, or a video could contain a series of images. Tracing these elements across different media types can reveal a fuller story, providing crucial context to the investigation.

Cross-media tracing allows investigators to connect seemingly disparate pieces of evidence. For instance, an image found on a suspect’s device could be traced to a video from a different source, linking the suspect to broader criminal activities.


Enhancing identification and verification


By comparing images against videos, forensic experts can verify the authenticity and origin of the content. This is particularly important in cases involving deepfakes or manipulated media, where distinguishing between genuine and altered content is challenging.


In cases like child exploitation, cross-media tracing can assist in victim identification. A still image, when matched with a video, can provide additional information about the victim's identity and the context of the abuse.


Strengthening legal cases


The ability to trace content across different media types strengthens the evidential chain. It can provide prosecutors with a more substantial case, as the interconnected evidence is harder to refute. Of course, cross-media tracing must be conducted with strict adherence to legal standards to ensure the admissibility of evidence in court. This meticulous approach enhances the credibility and reliability of the forensic investigation.


Thwarting criminals’ attempts to hide their crime


As perpetrators of digital crimes become more sophisticated, using various media types to commit and conceal their activities, cross-media tracing becomes essential in staying ahead of these tactics. The process often requires advanced forensic tools capable of analyzing and comparing a vast array of digital formats, further emphasizing the need for technical proficiency in digital forensic investigations.



Popular digital forensics tools


In the realm of digital forensics, especially when it comes to the investigation of illegal imagery and videos, law enforcement agencies rely on an array of sophisticated tools to aid in data recovery and analysis. Each tool serves specific functions, ranging from data extraction to detailed analysis, and plays a crucial role in the investigative process.


1. EnCase: EnCase is one of the most widely used forensic tools. Known for its robust capabilities in acquiring and analyzing data from various types of digital storage devices, EnCase allows investigators to conduct in-depth searches across large volumes of data. It is particularly effective in uncovering deleted files and hidden partitions, making it invaluable in cases where perpetrators attempt to conceal their activities.


2. FTK (Forensic toolkit): FTK is another comprehensive tool used for digital investigations. It excels in processing and indexing large amounts of data, allowing for efficient searching. FTK’s strength lies in its ability to organize and present data in a user-friendly manner, which is crucial when dealing with complex cases involving a vast array of digital evidence.


3. Cellebrite: Specializes in mobile forensics, providing solutions for data extraction from mobile devices. It is capable of bypassing certain security features on smartphones, making it essential in cases where mobile devices are a primary source of evidence. Cellebrite’s tools can retrieve data such as call logs, messages, photos, and even data from specific applications.



Videntifier Technologies


Our hash-matching software is designed to rapidly scan and identify illegal content. By creating a digital fingerprint for videos and images and comparing it against a database of known illegal content, Videntifier helps your team quickly identify harmful material across various platforms and devices.








Protecting investigators from recurring exposure to traumatic content


When dealing with illegal imagery and videos, the well-being of the investigators is an aspect of paramount importance. This dimension adds a layer of complexity to the already intricate digital forensics procedures.


Trauma-informed approach


During the preservation stage, it's crucial to acknowledge the potential emotional impact on investigators handling traumatic imagery. Establishing protocols that limit exposure and providing psychological support are key to safeguarding their mental health.


Maintaining well-being with efficiency


While collecting evidence, investigators are exposed to distressing content. It’s essential to design the collection process to minimize direct exposure. Automated tools and filters can be used to shield investigators from unnecessary exposure to traumatic imagery. Utilizing advanced software for categorizing and analyzing imagery can reduce the amount of distressing content directly viewed by investigators.


Responsible content review


The analysis phase often requires investigators to view illegal content directly. Implementing support measures, such as regular mental health check-ins, offering counseling services, and rotating staff to reduce continuous exposure, can help mitigate psychological risks.


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