> If someone disappears, their spouse gets put on the list of persons of interest.
That's because there is a relationship and historically the occasional spouse has been implicated in the murder of their other half.
> So do the last people seen with them.
Proximity means they might be witnesses, not immediately suspects.
> For each one, the police see if there is a case to be made, or if they known anything that could help, and then move on.
Yes. But they don't place everybody that was in a 10 mile radius around the crime scene on their list of suspects because they spoke the name of the victim out loud in the three weeks preceding the crime. And that's roughly the level this is at.
That's because there is a relationship and historically the occasional spouse has been implicated in the murder of their other half.
> So do the last people seen with them.
Proximity means they might be witnesses, not immediately suspects.
> For each one, the police see if there is a case to be made, or if they known anything that could help, and then move on.
Yes. But they don't place everybody that was in a 10 mile radius around the crime scene on their list of suspects because they spoke the name of the victim out loud in the three weeks preceding the crime. And that's roughly the level this is at.