Tape recording someone at work without their knowledge

Does anyone know the California law for audio taping someone at work without their knowledge.
Here’s the case.

I have 2 guys at work that go out of their way to make life harder for myself and other co-workers. Pretty much sabatoging things, but in a manner where no one sees them doing these actions.

I work for a wholesale grocery store chain. An example situation would be them knifing bags open from underneath, and then when you go to lift the bag, it’s entire contents spill to the ground, destroying hundreds of dollars of product. Since no one saw anyone commit any heinous act, the company assumes that the bag came defective from our vendor.

Of course, this comes out of my company’s pocket, and not mine. But when I have gone down to our receiving dock, loaded up my supplies, and then get thwarted, it’s a waste of time for me. And it looks bad on my job performance, ie. i cant get the work done in time.

These guys, every once in a while, love to brag about what they can get away with. Of course, this is done with no manager or superior present. So it boils down to my word against theirs.

So is audio taping them at work without their knowledge against the law in my state of California? Is there a strict right to privacy?

For people in other states, what are the laws in YOUR state?

My job has no provisions for or against taping. So I dont have a fear of losing my job. Since I work in a grocery store chain, our words can ALMOST be heard by the general public as they walk by and shop.

I dont know if any of you can relate or empathize with smug people at work that know they can get away with making your life harder.

I believe in some staes it’s legal to tape phone conversations as long as one party is aware of the taping, but illegal in all states if neither party is aware.

Can We Tape

Source: http://www.gannett.com/go/newswatch/2002/april/nw0405-8.htm