I've been picking up NPCs, however there are a few who refuse to show up on the party list. I've verified they are assigned to me and at the same location.
Any idea why they refuse to party with me? I don't smell that bad. Do I?
Those npcs were previously arrested and therefore can't be added to your party because nothing has been programmed to release npcs if they were arrested by someone else.
If you look around the city I've got a hundred npcs there myself and experienced the exact same problem.