Final answer:
Manual access in digital forensics is needed when phones cannot be detected or accessed by standard software. It involves hands-on review with documented evidence and is crucial for preserving evidence in legal contexts.
Step-by-step explanation:
Manual access is used when phones cannot be detected or accessed as a volume or filesystem. Manual access requires that the phone be reviewed by hand, with pictures and notes preserved to document the contents of the phone. This process is often employed in digital forensics, particularly when automated tools fail to recognize a device or when the device's filesystem is not accessible using conventional methods. These situations can arise due to various reasons, such as when the device is damaged, locked, or employs non-standard storage protocols that computer systems and digital forensic tools are unable to interface with automatically.
In the field of digital forensics, professionals meticulously inspect the device, often using specialized equipment to visualize and capture the contents displayed on the device's screen. This manual inspection is critical in legal contexts, where preserving and documenting evidence in its original state, untranslated by any form of software, is necessary. It ensures that all data is accounted for, including potential evidence that could be overlooked by automated scanning tools.