Fairly recently it seems that even if your sim stays on the lot, the "kidnapped" sim's needs will "miraculously" regenerate. I had my (female) apartment-dwelling sim trap a neighbor who had repeatedly invited himself over with an "oh, you don't mind, do you? Well even if you do, I'm staying anyway" bit. And as a woman who has lived alone in a city, that's scary. (And at least when I was living alone in a city apartment, I had a loud dog... in-game, this was just before pets was released.)
He stayed trapped, and using the "show sim info" mod, I could check his needs. But he would randomly stop starving without actually eating or getting out of the room he'd been trapped in by the sim whose apartment he had invaded.
Criminal sims seem to have some crazy protections..