Flash mob

Inmate 1: So, why are you here?

Inmate 2: I killed 8 people

Inmate 1: crazy! how?

Inmate 2: headshot

Inmate 1: but, why?

Inmate 2: well, it's complicated, i thought they were zombies

Inmate 1: and they weren't?

Inmate 2: they were normal teenagers, it was a zombie flash mob, so they were dressed as zombies
and acting as them, but they were normal people

Inmate 1: so it was all a big misunderstanding then

Inmate 2: pretty much


Inmate 1: the judge didn't see it that way?

Inmate 2: no, he said I should have known


Inmate 1: he didn't considered that you're too old to know what
 flash mob even means, or that young people would do those things

Inmate 2: exactly


Inmate 1: have you declared yourself insane?

Inmate 2: no, but I admitted i made a mistake, said it wouldn't happen again,
but it wasn't enough for them.

Inmate 1: not a very forgiving society

Inmate 2: they believe in punishment, they even want to punish you for
something you didn't even know was a mistake

Inmate 1: how could you have known?

Inmate 2: that's what I said, I was hoping to become a hero
or maybe not that, but I was thinking about surviving, you know when you
see zombies you start thinking that your species has to survive and if you don't
kill them your species would go extinct.

Inmate 1: basic biology

Inmate 2: Yes, it was my self preserving instinct that triggered and
I was just doing what had to be done in to enssure the continuity of my species

Inmate 1: our species

Inmate 2: flash mob...

Inmate 1: pfff...

Inmate 2: how about you? why are you here?

Inmate 1: I killed 6 people

Inmate 2: were they zombies too?

Inmate 1: no, they just pissed me off

Inmate 2: fair enough