Mobile Phone Evidence: The Modern-Day Smoking Gun in Forensic Investigations

In the early days of my policing career, it was rare to catch someone in the act. I can count on one hand the number of times I made an arrest right as a crime was happening.

Historically, investigators often had to rely on circumstantial evidence, witness statements, and physical traces left behind. Rarely did we have the luxury of seeing, in real time, what transpired leading up to, during, or after an incident.

However, in today’s digital world, mobile phones have become an indispensable source of evidence, a modern-day "smoking gun" in forensic investigations.

As society grows ever more dependent on technology, mobile phones have evolved from basic communication tools into comprehensive digital records of daily life. With everything from private messages and emails to location data and browsing history, phones have become invaluable sources of information for forensic investigators, providing unmatched insights into individuals’ intentions, movements, and behaviors.

Types of Evidence Extracted from Mobile Phones

Mobile phones are now at the centre of most forensic investigations, and with good reason.

The volume and diversity of data they hold can often paint a comprehensive picture of events surrounding an incident. Here are some of the primary types of evidence that forensic investigators commonly retrieve from mobile devices:

1. Text Messages, Chat Conversations and Communication Logs

Text messages, call logs, and communication histories are perhaps the most straightforward forms of evidence obtainable from mobile phones. Text messages can reveal conversations directly linked to criminal activities, including details of criminal planning, coordination, and threats. Additionally, call logs offer a timeline of communication that can help investigators establish connections between suspects or alibi verification.

2. Location Data and GPS Tracking

Most modern phones have GPS capabilities, and applications often store location data. Investigators can analyze this data to pinpoint the exact whereabouts of a person at specific times. This evidence can confirm a suspect’s proximity to a crime scene, trace movements before and after an incident, and even establish patterns of behavior. When corroborated with other evidence, location data can be critical in validating witness accounts or disproving alibis.

3. Social Media Activity

In today’s society, many people openly document their lives on social media platforms. Photos, status updates, check-ins, and live videos provide a public trail of activities and connections. Social media can reveal everything from relationships between individuals to gang affiliations, providing investigators with insights into a person’s motives or state of mind. Even private messages on social platforms can be obtained with the proper legal procedures, further expanding the digital landscape of an investigation.

4. Internet Search and Browsing Histories

An individual’s search history can be a powerful indicator of their intentions, state of mind, or even potential criminal behavior. For instance, searches on how to carry out certain acts or avoid detection can be highly incriminating. Browsing histories can also establish interests, patterns, or connections to other suspects.

5. Email and Application Data

As mobile phones have evolved, so have the ways people communicate. Encrypted messaging apps and social media platforms are now common ways for individuals to send sensitive information. Investigators with access to a suspect’s device can retrieve emails, in-app messages, and even financial transaction data, shedding light on connections or potential motives.

6. Photos, Videos, and Audio Recordings

Media files can serve as some of the most compelling evidence, offering visual or audio representations of events. Photos and videos taken on a device can contain metadata, including timestamps and GPS data, that helps confirm the authenticity of evidence and place suspects or witnesses at the scene of a crime. Additionally, audio recordings can reveal confessions, threats, or other critical statements.

7. Deleted Data

Forensic investigators have the tools to retrieve deleted data, which often includes conversations, photos, and files that suspects may have attempted to erase in an effort to hide incriminating evidence. Advanced tools and techniques allow investigators to recover these deleted files, often providing the last piece of the puzzle in complex cases.

Secure by design

Why can't you just plug it in and press go ?

Modern mobile phones are designed with robust security features, often posing significant challenges for forensic examinations. Factors such as the device's make, model, and operating system can greatly influence the extent of data that can be accessed and the types of examinations that can be performed.

Examining a mobile phone forensically is far from a simple “plug-and-play” process. Unlike general data transfers, forensic examinations involve complex procedures that must carefully preserve data integrity and adhere to legal standards. Each device presents unique challenges, from security locks and encryption to differing operating systems and proprietary features, which require specialised tools and expertise to navigate.

The “plug it in and go” myth couldn’t be further from reality in forensic work, where each examination is a meticulous operation tailored to the specific complexities of the device in question.

Some devices may only allow for an advanced logical examination, which retrieves visible files and metadata, while others might permit a full file system extraction that provides more extensive access to app data and system files. In rare cases, a physical extraction might be possible, capturing a complete bit-by-bit copy of the device’s memory, but this often requires specialized tools and is limited by the security architecture of newer devices. These considerations mean that forensic examiners must carefully assess each device’s specific characteristics and security features to select the most suitable approach for retrieving evidence.

Pre Examination Considerations

Before undertaking the examination of a mobile phone in a forensic investigation, forensic examiners typically ask key questions to ensure the process is thorough, legally sound, and that the data retrieved is relevant.

1. What Are the Legal Requirements and Authorisations?

• Has a warrant or consent been obtained to examine the device?
• Are there specific legal restrictions or privacy laws that apply to this case or type of device?
• Are there any limitations on the type of data that can be accessed or extracted?

2. What Is the Scope and Purpose of the Examination?

Defining the scope of a forensic investigation is crucial to achieving a positive outcome. A clear scope sets the boundaries for what data should be examined, aligns the investigation with legal and procedural requirements, and ensures that the analysis remains focused on relevant information. Without a well-defined scope, there’s a risk of collecting excessive data, which can overwhelm investigators and compromise the case by introducing irrelevant or inadmissible information. A focused scope helps to streamline the examination, maintains data integrity, and ultimately supports building a stronger, more persuasive case. When the scope is established correctly from the outset, the investigation is far more likely to deliver precise and actionable findings, leading to a successful resolution

• What specific information or types of data are relevant to the investigation (e.g., text messages, photos, location data)?
• Is the examination intended to gather evidence for a criminal case, civil case, or internal investigation?
• Are there any specific dates, times, or events that are relevant to the investigation?
• If the data was deleted, when was it deleted?

3. What Type of Device Is Being Examined?

• What is the make, model, and operating system of the mobile device?
• Are there any technical specifications or features (such as encryption) that could impact data extraction?
• Are there any unique characteristics or applications on this device that require specialised tools or knowledge?

4. What Is the Condition of the Device?

• Is the device operational, damaged, or in a specific mode (e.g., locked, airplane mode)?
• Does the device have a low battery, and does it need to be preserved or stabilised to prevent data loss?
• Are there signs of tampering or attempts to delete or conceal data?
• What state is the device in? i.e. is it powered off or still running ?

5. Are There Known Security Measures on the Device?

• Does the device have a passcode, biometric lock, or other security feature?
• Are there any encryption settings or secure containers (e.g., secure folders, apps requiring secondary passwords)?
• Are there tools or credentials available that can help bypass security features legally?

6. What Are the Potential Sources of Data on the Device?

• Are there specific apps, files, or types of data relevant to the investigation (e.g., messaging apps, social media, browsing history)?
• Are there cloud services or external backups (like Google Drive or iCloud) associated with the device?
• Does the device sync with other devices or have connections that might be relevant (e.g., Bluetooth devices, laptops)?

7. Are There Any Known Risks or Limitations?

• Are there any specific risks related to handling this device (e.g., tampered devices, malware)?

8. What Reporting and Documentation Will Be Needed?

• What format is required for the final report or presentation of findings?
• Are there any special requirements for documenting the process, findings, and conclusions?
• Who will receive the report, and are there any redactions needed for privacy or legal compliance?

By addressing these questions upfront, investigators can plan an effective and compliant approach to mobile phone examinations that aligns with legal, technical, and investigative requirements.

Why does a mobile device need to be examined forensically ?

A forensic examination of a phone is critical to ensure that the evidence remains accurate, reliable, and legally admissible. When phones are examined forensically, specialised tools and methodologies are used to preserve and verify the original data, including timestamps and date information, which are essential in establishing timelines and corroborating events. A proper forensic process prevents accidental or intentional alterations that could compromise the evidence.

This preservation is vital for legal admissibility, as courts often scrutinise digital evidence rigorously to confirm its integrity. A carefully conducted forensic examination ensures the evidence withstands legal challenges, meets strict chain-of-custody standards, and maintains credibility in court, thus supporting justice and the truth.

Reach out for more information        

Contact Alvarez and Marsal Australia today, and let our digital forensic experts provide you with the support you need to navigate through these challenges.

Call today to discuss your needs on +61 0458 898 405 or [email protected]