Screenshots as criminal evidence: do they have value in a trial?
A very frequent question in the digital age is whether a screenshot of some threatening messages serves as evidence. The answer is not a simple yes or no: screenshots can be valid evidence, but their value depends on how they were obtained, how they are presented and whether their authenticity can be established.
Today a large part of conflictive interactions, such as insults, threats, harassment or fraudulent agreements, leaves a digital trace, and the screenshot is often the first impulse to preserve those communications. The problem is that screenshots are one of the most easily manipulable forms of digital evidence: with an image editor or specific applications, anyone can alter the text, add non-existent messages or change names and dates.
The Supreme Court has established a doctrine that can be summarised thus: screenshots are admissible documentary evidence; their evidentiary value is not automatic or presumed, so whoever provides one bears the burden of establishing its authenticity if the other party challenges it; when both parties acknowledge the authenticity, the screenshot has full value without additional verification; and when it is challenged, it needs to be complemented with some means that establishes that it has not been manipulated.
The ways to manipulate a screenshot are several: direct editing of the image, the use of applications that generate fake conversations with a realistic appearance, the creation of fake accounts in another person's name or the partial selection of the conversation omitting the context.
There are different methods to establish authenticity, with different degrees of solidity. The most robust is the notarial record drawn up when the notary directly views the content of the original device; its evidentiary force is very high owing to notarial public faith, and it also preserves the content before it can be deleted. Computer expertise analyses the original device, its metadata and the application's database. Corroboration by other evidence reinforces credibility indirectly, although it is usually insufficient on its own. And the opposing party's acknowledgment eliminates the need for technical verification.
Whoever has relevant screenshots must act quickly, because conversations can be deleted; keep the original device without formatting it; consult their lawyer about the appropriate authentication method; and present them at the appropriate procedural moment. If the screenshots harm the accused, the defence may expressly challenge their authenticity at the appropriate procedural moment, since a late challenge may be interpreted as acceptance; request a computer expertise that detects manipulations; provide the full content of the conversation if only fragments were presented; and point out that the messages, even if authentic, admit another interpretation.
It is worth being clear about the difference in evidentiary value between a simple screenshot and a notarial record: the former can be challenged without great technical basis, it being enough for the other party to deny the messages; the latter enjoys the notary's public faith and is very difficult to question. When the evidence is relevant, the cost of the notarial record is more than justified by the solidity it provides.
