My question involves court procedures for the state of: CA

I was defrauded by the seller of a property that I purchased. I now want to rescind the sale contract and have the money returned to me. He has refused.

About ten years ago, the seller, whom I knew socially, worked for a county government office. He told me how he often received kickbacks in exchange for awarding service contracts to cooperative vendors/providers and asked me if I was interested in bidding on a contract (I was not). The statute of limitations for the county to go after him for corruption has passed, however I believe he would still be liable to the IRS for tax evasion, by failing to report the kickbacks as income.

I know I can't threaten to report him unless he pays me - that would be extortion or blackmail. However, what if we simply included the defendant's prior statement, admitting that he received kickbacks, as character evidence in the complaint that we file, or even in a demand letter? There would be no threat to expose or report him, or to in any way use this info against him if he does not settle. Is there a risk that this could this be interpreted as as blackmail or extortion by a court? I haven't discussed this matter with him since he originally made the statement.

Based on what I've read, character evidence would be inadmissible in this (civil) case, so it would be thrown out later. But at least the other side would know that this is out there.

Thanks in advance.