If an NPC is killed, does a new one spawn to take it's place?

For example if I were to kill my physician's current assistant, would another "Caretaker/Nurse" NPC spawn to replace them so my doc isn't left to run the show alone?

I believe so but if not I think there is a cheat code you can use to regenerate missing people.

Yes they do.
My royal advisor was throwing eggs at my sim while he was in the stocks. He wont do that again. Ever.