When The Storm Blows By: Will You Be There? Part 4

This is part of a series and must be read through the end to understand. It's long I know but only way to get full effect. Kind of old too but don't hold that against me.

Brooklyn

There's a new girl,
Mercedes is her name.
She went to the mall
With us this afternoon.
She's kind of shy though.
She always seems relieved,
Or apologetic,
Like we're saints or of angelic nature
Or something like that.
There's something up with her
Family, I think.
It's been a week
Since I first met her.
I noticed the bruises
On her side, too.
Dad, I presume.
Always where no one can see.
As I turn up the radio,
I think of the screaming
Coming from downstairs.
I pick up the knife
And make a smooth
Incision on my leg.
I know how you feel,
Mercedes,
I know how you feel.