Cal. Rev. & Tax. Code § 3967

If the court determines that none of the defendants have any right, title, interest, lien or estate in the property, the court shall render its final decree quieting the plantiff’s title under the tax deed and, if any of the defendants claims to be the owner of or have an interest in a special assessment, which special assessment the court determines to be invalid or inferior to plaintiff’s title, the decree shall direct that the treasurer cancel the assessment on his records.