Legal Question in Real Estate Law in California

The general rule is that a forged deed does not pass title. You should repost this question in the category for Florida attorneys to answer, as that jurisdiction may have time limits or special rules for contesting the deed, and special rules governing adverse possession.

The part about the half sister signing sounds more like an admission of guilt than an act that would render the deed null and void. In California, a deed with a forged signature of the supposed grantor is indeed void. Vaca Valley & Clear Lake Railroad Co. v. Mansfield (1890) 84 Cal. 560.

Florida law, however, will govern here; it might not be the same. A greater problem is how Florida will deal with the long duration of time (about 16 years) during which the forgery has been unaddressed (and perhaps undiscovered?). Whoever is occupying the house may have acquired rights by adverse possession, or suit to recover possession may otherwise be barred by a statute of limitations or the equitable doctrine of laches.

I suggest you re-ask this as a Florida question, and add to your facts some information about (1) how and when you discovered the forgery, (2) who has been in possession of the property for the last 16 years, if you know, (3) whether the deed is recorded, and (4) who has paid the property taxes over the last 16 years.

Mr. Whipple is correct. I would also add that if the property has been sold for fair market value without the buyers knowing of the forgery, the buyers get to keep the house under any state law I've ever heard of.