When looking at digital evidence you might expect the content of a file to of the most important. But in many cases, the information surrounding the file is of equal importance. The metadata of a file can contain many interesting facts.
Most files have the basic types of metadata, like file name, file type and MAC times. Some files can contain other information like geolocation, program used to edit it and more.
There was a case in the US some years ago where the Police were not able to find a suspect for several murders. In a scheme trying to fool the killer into contacting them, the Police stated in a local newspaper that he could communicate safely with them via floppy disc. And as they hoped, the killer – in an effort to gloat on them not catching him – sent the Police a floppy disk containing not only a letter but also a deleted Word file. This file contained information about who and where it was created, which led them to Dennis Rader who later were convicted to 175 years in prison. (Wikipedia, 2016)
But it is important to remember that the metadata can be easily changed. The MAC-times (Modified, Accessed, Changed) can quickly and easily be altered to what you want via simple commands in Linux.
Wikipedia (2016) Dennis Rader
https://en.wikipedia.org/wiki/Dennis_Rader (Accessed: 14 December 2016)