I love that show! :) "Good people" is very general in this context. It basically just means decent people - productive members of society. You'll see this phrase used often when talking about people dying - "We lost a lot of good men out there." -> a stereotypical line used when referencing soldiers dying in war. "A lot of good people died that day" -> maybe in reference to a tragedy like a shooting or terrorist attack or something. As for why we refer to them as "good" people...I don't know! Perhaps to emphasize that it was a bad thing that happened that caused them to die?

It could mean people who were good at their job, like good police officers died trying to catch the guy. Or, it could mean virtuous people died trying to catch him. To refer to someone as a "good person" could mean that they are a capable person or a virtuous person, sometimes both. It is difficult to know which the person meant in your TV show without context, but if a criminal is a "bad" person (who acts immorally) then it is logical to assume that by "good" person, they mean somebody who acts morally. I hope this helps!

means those people who were looking for him and they lose their good seols