Proving Discrimination in California Against An Employer 

Although every case and every situation is different, there are a few fundamental principals that an employee who consider making a discrimination claim should know about California employment law in the context of proving discrimination:  

1. To make a claim for discrimination you must show that you suffered an adverse employment action, such as demotion, termination, or failure to hire, because you are a member of protected class, i.e. due to your age, sex, race, disability, religion, sexual orientation, familial status, and a few other classifications. 
2. Simply being a member of a protected class and being subjected to adverse action is insufficient to make a discrimination claim. For instance, just because you are over 40, or gay, or black or Jewish and you were terminated, doesn't alone prove that the reason for your termination was that protect characteristic and not some other reason, fair or unfair. The "because" part requires that you show that it's your protected classification that was the reason or one of the substantial reasons for your termination.  
3. The burden of proof in a discrimination case is on the claimant. This means that the employer doesn't have to prove that they didn't discriminate against you. It's your job to prove that the reason for your demotion or dismissal was discriminatory and not some other reasons. 
4. False reason for termination alone is insufficient to prove discrimination. The courts have reiterated over and over that lying is not the same as discriminating, although in conjunction with other evidence, it can support a discrimination case.   
5. How other employees of the same protected classification are treated may have some relevance, but unless you can show a strong pattern, i.e. where dozens of employees of the same classification are replaced with other employees, this will not be sufficient evidence to prove discrimination. 

In light of the above, if you are considering making a discrimination claim against an employer, you must have some evidence of discriminatory animus toward you. This evidence can be (1) documents, e-mails, social media message or any other documents in which a decision maker makes it clear in so many ways that they don't want you or want to replace you for discriminatory reasons; and/or (2) witnesses that heard decisions makers (your managers) say at least something that would suggest that the reason they terminated you was discriminatory. It's worth asking your (former) co-workers if they have any such information, as you might surprise what you can learn about your termination from them. Even one document or one witness with such information can make a case.