I started Deus Ex and I was going for the pacifist achievement . Unfortunately I killed a civ while dicking around in Detroit  . 
So now I have the following questions 
1: Should I restart ? I'm about 3 hours in.
2: Where can I get the stun gun , if I didn't pick it in the chopper ?
3: Where can I get some extra tranquilizer darts ? ( I already went to the gas station sold out)

No; deal with it.

Mario and Luigi are not owls.

I sort of know how you feel. I killed a couple dudes during the tutorial, but in the 6 hours that have followed, I haven't killed a soul. Wishing I hadn't, but I guess I don't mind the option to play however suits the situation, so I'm free to kill some dudes at some point. Do a kill-free run later on. Make a choice, no matter how bad, and commit to it. Keep going!

i've actually had a bug where i shot someone with the tranq gun, come back a few hours later and he was dead instead of asleep.    I was trying to go for a no kills achievement too but at this point there's no going back.

@left4doof:

The game autosaves, there should be a save of at least after you finished the first mission, so you can load that up instead of restarting the whole game.

I have a dilemma too, if I choose the stun gun in the chopper, can I get a silenced pistol later or is that impossible? Also, if you preordered the game, do you get the bonuses every new game you start or just the first one?

@ajamafalous: Krogans don't wear hats .

@kuz101 said:

I have a dilemma too, if I choose the stun gun in the chopper, can I get a silenced pistol later or is that impossible? Also, if you preordered the game, do you get the bonuses every new game you start or just the first one?

There are pistols all over the place. You just need to buy a silencer and attach that to the pistol.

You get the bonuses at the start of each game.

@Tennmuerti: Cool, thanks for the response.

I started Deus Ex and I was going for the pacifist achievement . Unfortunately I killed a civ while dicking around in Detroit  .  So now I have the following questions  1: Should I restart ? I'm about 3 hours in. 2: Where can I get the stun gun , if I didn't pick it in the chopper ? 3: Where can I get some extra tranquilizer darts ? ( I already went to the gas station sold out)

I've been playing this game for like 7 hours, haven't killed anybody yet. Relying only on the stun gun and knockouts. But where the fuck do I find the tranquilizer gun? I probably breezed right past it without even knowing. Knowing would make this game a little easier.