I was accused of a theft that I did not commit in February, what are my options?

In mid February of this year, a small amount of money was missing from the petty cash of my former employer. At the time, I was a store manager and I was held responsible for these sort of matters. I thought that it was either a cashier issue or that the money could have been misplaced. A few days later, I receive a call from an loss prevention representative stating that our store was under investigation for theft. Of course this worried me, if it got to HR there must be something more that I was not aware of. I believe it was about a week later, that I received another call from my district LP saying that they have 2 witnesses and statements saying that I was one would stole the cash. To make it clear, I did not take the money. He asked me for a statement about the incedent and then the call was ended. At the end of the week, the LP resentative showed up at my store with a check in hand and told me this would be my last day and I would no longer be hireable with this company. Before I was asked to leave, we conferenced in my old boss, who then basically redescribed what was told to me on the prior phone call and said she was disappointed in me. This happened as the economy entered it's rut and as a result I have been unable to find a career that has been able to provide me with the means that I have become accustom to. In California what are my options and what steps do I need to take?