In several episodes of Columbo, he talks about his wife, but we never see her. In one episode based in Mexico, she is even invited to lunch, but leaves at the last moment. This seems to happen a lot - ...
So I was watching the old Columbo series, and saw a pattern again and again. Many times, there were no clues against a certain suspect, but still Columbo zoomed in on him/her, and kept asking ...