So... I have no idea how they thought it would apply in this case, or what investigators had in mind.
That said, very broadly and in theory, in today's world almost any data point can be predictive of almost any behaviour. This is the premise of ad-tech. Less amorphously, you could probably construct a theory. People reading the story within a certain window of time, within a certain geographical area... etc.
Evidence, probable cause & reasonable suspicion as legal terms, that's a different matter.
This isn't really true, though, even in theory. In practice it's much worse, as we aren't very good at using even large collections of data points in most cases to predict behavior. We can in some very few, narrow contexts occasionally do better (sometimes much better) than a random guess once in while.
That said, the one relatively broad concept where "we" consistently do better than random guesses is ad-tech, which is where the bulk of private efforts to this effect are concentrated currently. The premise here is quite literally "every data point is predictive of behaviour," behaviour being stuff related to the goals of advertisers.
It's not a huge leap to suggest that fb & adwords' system can be used to predict crime, insurance claims, HR-related stuff etc.