About a decade ago, in the previous town I lived in, a late 50s man's wife went missing. The word was she'd been attacked, assaulted and most likely murdered. We got together at the 'town green' and made plans to out 'missing' flyers in our back windows. The husband had printed a bunch out, and we all spoke with him in some detail. I spent 20 mins with him, just trying to be human towards a man in his hour of grief.
A week later, her headless torso was found chopped up in a suitcase on one of the bay waterfronts. The evening of the announcement, the husband threw himself off a bridge and having left a confession note. Her head was never found.
It was a massive wake-up for me as I felt I had a great read of people. I still think I have a decent read, but yeah, not always obviously...