Which comic did this event occur?

Note I'm just wondering which ones, and they have to be new 52, not in the mood to read anything older then that.

Batgirl getting shot in the back.

Roy Harper becoming Arsenal, the events leading up to it and the event itself.

And if it exists (New 52) the series of nightwing, red hood and Red Robin when they were still Robin.

Thanks in advanced :)

I haven't been reading the new Batgirl but are you referring to when Joker shot Barbara Gordon? That was waaaay before new 5 (1988 IIRC). And Roy has always been characterized as Arsenal in new-52 (unless you mean an issue that details some of his backstory, then I don't know off-hand).

The Killing Joke. Batgirl is shot (Before New 52)

New Titans #99 Harper first appears as Arsenal. (Before New 52)

Haven't been keeping up with Batman in the New 52 but I don't think there is an ongoing which regularly has any of them as Robin.

There isn't. Maybe the OP doesn't know exactly what the New 52 is (or any of the changes). I find nothing wrong with preferring to read more modern comics (I know I do), but it seems like a very odd request. Might as well said "When did COIE happen in the new52? I want to read that"

Fairly new to comics (somewhat, it's complicated), and didn't really feel like going into older series. But there isn't any new 52 series that shows the back story of when Harper becomes Arsenal? Not even in the Red Hood and the outlaws?

Have they finished off the Batgirl New 52 series? I guess if and when they do that would be when she get's shot.

they haven't really shown all of Roy's origin in the New 52 yet...all we know is that at one point he worked for Green Arrow, Ollie fired him, he became an alcoholic and suicidal, Killer Croc talks him out of suicide, ends up in prison, is broken out by Jason Todd, then joins the Outlaws...that's pretty much it

Barbara has already been shot and healed in the New 52...she was shot way back in the Killing Joke back in the 80's

most of the Bat Family's past from prior to the New 52 is still in tact...so the Killing Joke still happened

as for the Robins....they've only shown bits and pieces of Dick as Robin....like I said most of the Bat Family's history remained intact so Damian has been the only Robin in the New 52 that we've seen as Robin....they've shown a few flashbacks where Dick was Robin but that's about it, Tim was never Robin..he has always been Red Robin in the New 52 and they've only shown a few flashbacks of Jason as Robin as well

Uhm, so is New 52 mostly a continuation of what happened in the past? Or does that only apply to some?

The New 52, for the most part, is a re-telling of sorts for most titles. A couple of them didn't really change much and kinda picked up like the next issue of their respective series before Flashpoint. For example Green Lantern didn't change that much.

the New52 is not a hardwire reboot like everyone wants to make you believe, it keeps some of the more notorious stories,

Batgirl has not and probably will never be shot in the New52. yes it is an ongoing, so its not over, and doesn't look like it will be soon. the closest thing to this I can think of. is issue zero, this shows the event, but not anything more than just bits and pieces, this is a very old story, this is how she became the superhero, Oracle. they are proceeding like all that has happened already.

the back story on roy harper is the same thing, though it appears they kept a lot of his old storyline out of the new storyline. heres how it used to go, Roy becomes a heroine addict, Green Arrow kicks him off the team, roy gets a wife and baby, loses an arm, loses his daughter. I don't think any of that is in continuity (other than him being booted)

Robins.... yeah NO.... this is decades of stories we are talking of here, and the New52 has only been around for 2 years

2 years

2 years, is not even long enough for them to make flashback references to them being robins, buuuuttt... again read issue zero of Batman and Robin, theres a single panel dedicated to each robin, and their origin/induction into being robin.