Also good for spotting time travelers. Their Questionable Observer Detector (QuOD) can process any available video clips of groups of people present at the scene of event, spanning different times and locations to pick out any person who appears frequently in them. “The idea is that the person showing up unusually often as part of the crowd at these events may be someone that the police would want to talk to,” says Bowyer.
"Yeah, sure, buddy, you work in the building. So do the other 200 suspects we rounded up today, if you believe them. Don't worry, we'll make you talk."
On one hand, this seems to be unfair to people who want to get out and see things with their own eyes -- as opposed to staying home and seeing things through the eyes of a TV camera.
This seems to unfairly target the sort of people who show up in the aftermath of an "event" -- ambulance drivers, newspaper reporters, window glass repairmen, etc.
If this becomes commonplace, then honest people who don't want to be associated with crime might decide to leave the area as soon as they suspect something is not quite right -- with the unintended consequence that bad guys then become free to do whatever they want without any honest eyewitnesses.
On the other hand, I imagine that police might want to know what really happened here.
They want some honest person to tell them what happened.
The sort of people who work in the building, or frequently visit a location, are more likely to be able to notice that something is not quite right.
The sort of people who stick around for a little longer and watch events happening when they sense that something is not quite right -- these are exactly the kind of people that might have some clue as to what actually happened there, and so exactly the kind of people that "police would want to talk to" when the police want to know what really happened.