Walls and Ceilings - Identifying a load bearing wall

I've been building a new closet into my bedroom, and just started knocking down the old closet.

I tore down the drywall, and noticed a double top-plate in the lumber behind the drywall. Here's a photo of the top-plate:

http://www.antunkarlovac.com/stuff/double_top_plate.jpg

... and here's a picture of teh wall itself:

http://www.antunkarlovac.com/stuff/is_load_bearing.jpg

All along I though that this must be a partition wall, since the way it's laid out looks like an afterthought.

Is there any way I could tell for sure if this is load bearing? If it is, what are my options?

Thanks in advance,

Antun

In the attic, if there are horizontal framing members ending on, or joined over, are roof bracing ending on it, its a bearing wall and will require a header.

Thanks - It turned out to be load bearing after all. I couldn't get to the attic space at first, but my neighbor (who's pretty knowledgable on construction) came round adn confirmed it. Then when I drilled into the attic space, I found the lapped beams.

My house is still standing after all.

-Antun

Of course it is, you have only removed the wall covering, not the structure.
Do you need further assistance in installing headers or temporary support walls?