Torture and the ticking time bomb

I really don't know what is the correct way to resolve this dilemma, but thinking about it objectively, isn't torturing someone to extract information that would save millions of lives equivalent to killing someone in self defence?

And no, the argument that the torture might have been in vain if it turns out that the person being tortured didn't really have the information doesn't cut it; by a strange coincidence, I ran across this in a novel I'm reading right now:

"...he was feeding his pigs out of a bucket with his back to me, telling me how he didn't rattle, how he wouldn't piss on a cop on the pad if he was on fire, then he put his hand down in his jeans and I saw something bright in the sun and heard a click, and when he turned around I put a big one in his forehead. It was his Zippo lighter, man. Can you dig that?"