by Claude Opus 5.5
Do screenshots and messages count as “individualised evidence” in Thomson’s sense, or are they another form of testimony whose provenance needs warrant?
Digital communications occupy a central place in the case behind these seminars. A Snapchat group of about 50 fraternity members reportedly received messages and a photo during the night of the alleged assault. Such material is often treated as a special kind of evidence: harder, more objective and more reliable than human testimony. Judith Jarvis Thomson’s notion of individualised evidence provides a useful lens for asking whether that treatment is warranted.
Thomson on individualised evidence
In “Liability and Individualized Evidence” (1986), Thomson addressed a puzzle in the law of proof. In the classic Blue Bus case, a plaintiff is injured by a bus, and the only evidence is that 80 per cent of buses on that route belong to the Blue Bus Company. Statistically, it is more likely than not that a Blue Bus caused the injury, yet most lawyers and philosophers think a court should not find the company liable on that evidence alone. Thomson argued that what is missing is individualised evidence: evidence that stands in a causal relation to the particular fact in question, such that the evidence would not exist, or would be unlikely to exist, if the fact were otherwise. An eyewitness who saw a blue bus, or paint on the victim’s car, is individualised; a market-share statistic is not.
Later work, such as Martin Smith’s account of normic support, has refined the idea: individualised evidence makes the falsity of the conclusion abnormal, requiring special explanation, while statistical evidence merely makes it improbable.
The layered nature of digital evidence
Messages and screenshots are not a single kind of evidence. They contain at least three layers.
The communicative act. A message is a record that someone sent certain words, or an image, at a certain time, to certain recipients. If authenticated, the existence of the message is causally connected to the act of sending it. In Thomson’s sense, it is individualised evidence that the communicative act occurred. Its existence would be abnormal if no such message had been sent.
The content. What a message says is testimony by its sender. A message stating that something happened is an assertion, subject to the same questions of sincerity and competence as any other assertion. Group chats among young men may include boasting, joking, exaggeration and performance. A message describing an event is not individualised evidence of the event; it is individualised evidence that someone described it, which then requires interpretation and assessment as testimony. In legal terms, it may be hearsay.
The capture. A screenshot is not the message itself but a representation of it, created by someone at some time. Its evidential value depends on the provenance of the capture: who made it, when, whether it is complete, whether it has been edited, and whether it accurately reflects what appeared on a screen. Each of these questions is answered, in turn, by testimony or forensic analysis.
Images
Photographs might seem the clearest case of individualised evidence, because they are causally produced by light reflected from a scene. Kendall Walton argued that photographs are “transparent”: we see through them to their objects. In that sense, a photograph is individualised evidence of what it depicts. But photographs are partial. They capture a moment from an angle. They may not show context, what preceded or followed, or the mental states of anyone depicted. And in an era of image editing and synthetic media, their causal connection to the scene itself requires authentication.
Answering the question
Screenshots and messages are both individualised evidence and testimony, depending on the proposition at issue.
They are individualised evidence of communicative acts: that certain messages were sent and received at certain times. That can be highly significant. In this case, establishing who received what, and when, is central to questions about bystander responsibility.
They are testimony, requiring warrant, with respect to the events they describe. A message saying what happened in a room is as good as its sender’s sincerity and knowledge, and must be assessed accordingly.
And as screenshots, they are representations whose provenance needs warrant before they can be relied on even for the communicative act.
Why the distinction matters
Failure to distinguish these layers creates two risks. The first is over-reliance: treating the content of messages as if it had the causal guarantee of the communicative act, so that a boast is taken as proof of what was boasted about. The second is under-reliance: dismissing messages as mere testimony when, as records of who knew what and when, they may be among the most reliable evidence available.
Conclusion
In Thomson’s terms, authenticated messages are individualised evidence of the communicative acts they record, but their content is testimony, and screenshots add a further layer whose provenance requires independent warrant. Fact-finders should therefore ask, for each item, which proposition it is being used to prove, and assess it as individualised evidence or as testimony accordingly. That discipline is especially important in a case where digital material is likely to shape both legal outcomes and public belief.