Which type of evidence includes electronic files, such as emails and text messages?

Digital evidence encompasses electronic files, including emails and text messages, making it the correct answer. This category of evidence is increasingly significant in modern investigations, as it can provide critical insights into communications, timelines, and the intentions of individuals involved in a case. Digital evidence is typically stored in a variety of formats and can be retrieved from various devices such as computers, smartphones, and servers.

Other forms of evidence, while also important, serve different purposes. Documentary evidence generally refers to any written or recorded information that supports a case but does not necessarily include digital formats. Impression evidence pertains to physical imprints (like shoeprints or tire treads) left at a crime scene and is not related to electronic files. Physical evidence, a broader category that includes tangible objects related to a crime, does not specifically address electronic formats like emails and text messages, which are uniquely characteristic of digital evidence. Thus, the identification of digital evidence is crucial for effectively gathering and analyzing information in criminal investigations.