No. I don't want you to stick around. I'd like to chuck you outside and tell you to sleep in the lake tunnel and get the hell away as soon as morning comes. But we're both practical men, aren't we?

I don't want you near anyone else without supervision. Sherlock's got enough of a fighting reflex that he got you off. But clearly you've got problems that might crop up. Especially if Al puts it about that you're a serial killer who murdered Dr. Suresh.

Someone's going to have to mind you. That's really the only punishment we have available here. Killing you isn't a guarantee to be permanent, and breaking you to the point you can't hurt anyone else is going to leave whoever's looking after you with more trouble than it's worth... bringing us back to the problem with death. [He's had ample time to consider all of this given the Joker, Sylar.]

So, you get to stay with us until there's someone I can trust to take you off of our hands and who's willing to shoulder that burden.